Fix bad lambda prototype in workingctx.fileflags()

osutil.c: use readdir instead of readdir64 Some systems (e.g. *BSD) don't have a readdir64 function - the regular readdir already uses 64-bit types. On other systems (Linux, Solaris, ...), if Python was compiled with large file support, Python.h will define _LARGEFILE_SOURCE and _FILE_OFFSET_BITS=64, so that any call to readdir will actually be a call to readdir64. If Python was not compiled with large file support, we probably don't want to define these macros to avoid ABI problems.

osutil.c: include Python.h before the other headers This is recommended by the Python documentation, since Python.h defines some constants.

Add osutil module, containing a listdir function. This is similar to os.listdir, only it returns a sorted list of tuples.

hgk: add basic usage and configuration documentation

hgk: add context menu visual diff action * * *

hgk: add debug-config command to pass configuration options

hgk: fix right-mouse button handling under macosx

Test *_ISLINK merge environment vars

merge: provide *_ISLINK environment vars to merge helper Sets HG_MY_ISLINK, HG_OTHER_ISLINK, HG_BASE_ISLINK in environment. Without these variables, it's impossible for the merge application to know whether the 'other' and 'base' files were symlinks in their original contexts. For the purposes of the merge they are always emitted as small text files.