discovery-helper: bail out if destination already exists

discovery-helper: move repository creation in a function This makes it easier to update this duplicated code. (we do a small output fix as we go)

discovery-helper: add an extra argument to generate only one repo This is useful to generate left and right in parallel when dealing with very large repositories.

wix: remove enum and future packages These were cargo culted from the THG installer code. I'm not sure what needs them in THG land. But the official MSIs certainly do not - at least not as direct dependencies. .. bc:: The Windows MSI installers no longer include the enum and future Python packages. Differential Revision: https://phab.mercurial-scm.org/D6101

wix: remove pywin32 This dependency was for ancient Mercurial versions. We recently removed it from the Inno Setup installers. So let's remove it from the WiX installers as well. .. bc:: The Windows MSI installers no longer include the pywin32 Python package. Differential Revision: https://phab.mercurial-scm.org/D6100

wix: remove sphinx and dependencies Sphinx was cargo culted into our install environment as part of emulating TortoiseHG's behavior. THG seems to install Sphinx in order to generate THG specific documentation. We don't appear to need Sphinx or any of its dependencies in the official WiX installers. So remove it. This shaves ~1MB off the size of the MSI installers. .. bc:: The Windows MSI installers no longer include the Python sphinx package and its various dependencies. Differential Revision: https://phab.mercurial-scm.org/D6099

wix: functionality to automate building WiX installers Like we did for Inno Setup, we want to make it easier to produce WiX installers. This commit does that. We introduce a new hgpackaging.wix module for performing all the high-level tasks required to produce WiX installers. This required miscellaneous enhancements to existing code in hgpackaging, including support for signing binaries. A new build.py script for calling into the module APIs has been created. It behaves very similarly to the Inno Setup build.py script. Unlike Inno Setup, we didn't have code in the repo previously to generate WiX installers. It appears that all existing automation for building WiX installers lives in the https://bitbucket.org/tortoisehg/thg-winbuild repository - most notably in its setup.py file. My strategy for inventing the code in this commit was to step through the code in that repo's setup.py and observe what it was doing. Despite the length of setup.py in that repository, the actual amount of steps required to produce a WiX installer is actually quite low. It consists of a basic py2exe build plus invocations of candle.exe and light.exe to produce the MSI. One rabbit hole that gave me fits was locating the Visual Studio 9 C Runtime merge modules. These merge modules are only present on your system if you have a full Visual Studio 2008 installation. Fortunately, I have a copy of Visual Studio 2008 and was able to install all the required updates. I then uploaded these merge modules to a personal repository on GitHub. That is where the added code references them from. We probably don't need to ship the merge modules. But that is for another day. The installs from the MSIs produced with the new automation differ from the last official MSI in the following ways: * Our HTML manual pages have UNIX line endings instead of Windows. * We ship modules in the mercurial.pure package. It appears the upstream packaging code is not including this package due to omission (they supply an explicit list of packages that has drifted out of sync with our setup.py). * We do not ship various distutils.* modules. This is because virtualenvs have a custom distutils/__init__.py that automagically imports distutils from its original location and py2exe gets confused by this. We don't use distutils in core Mercurial and don't provide a usable python.exe, so this omission should be acceptable. * The version of the enum package is different and we ship an enum.pyc instead of an enum/__init__.py. * The version of the docutils package is different and we ship a different set of files. * The version of Sphinx is drastically newer and we ship a number of files the old version did not. (I'm not sure why we ship Sphinx - I think it is a side-effect of the way the THG code was installing dependencies.) * We ship the idna package (dependent of requests which is a dependency of newer versions of Sphinx). * The version of imagesize is different and we ship an imagesize.pyc instead of an imagesize/__init__.pyc. * The version of the jinja2 package is different and the sets of files differs. * We ship the packaging package, which is a dependency for Sphinx. * The version of the pygments package is different and the sets of files differs. * We ship the requests package, which is a dependency for Sphinx. * We ship the snowballstemmer package, which is a dependency for Sphinx. * We ship the urllib3 package, which is a dependency for requests, which is a dependency for Sphinx. * We ship a newer version of the futures package, which includes a handful of extra modules that match Python 3 module names. # no-check-commit because foo_bar naming Differential Revision: https://phab.mercurial-scm.org/D6097

wix: move contrib/wix to contrib/packaging/wix We're trying to consolidate all our packaging code into contrib/packaging. Let's move the WiX files there. Differential Revision: https://phab.mercurial-scm.org/D6096

wix: remove hg.cmd This file is not referenced anywhere AFAICT. Differential Revision: https://phab.mercurial-scm.org/D6095

setup: include hgext3rd package in py2exe builds This is a core Mercurial package and we should always ship it. Differential Revision: https://phab.mercurial-scm.org/D6094