discovery: cleanup of variable names and comments

localrepo: give a sigh of relief when getting lock after waiting for it A message like this was sometimes shown when pushing: remote: waiting for lock on repository foo held by 'mercurial:20858' That could scare users, making them wonder whether the push actually succeeded. To mitigate that fear, issue an additional "warning" such as: got lock after 2 seconds The return value from lock.lock.lock() was unused - instead we return the delay. This also adds the first test coverage for waiting for locks.

convert: add tagmap option Tests have been updated.

convert: add tagmap logic Previously, there was no way to rewrite tags on the fly while converting. Now, we add similar logic to branchmap to provide a way to map old tags to new tags. Currently, this is not enabled since there is not yet a command-line option.

convert: avoid updating tags when there is nothing new Previously, when converting from a mercurial repo there would be an extraneous commit at the end of the convert process that would rewrite tags. Now, we check if there are any new tags before doing this rewriting.

convert: compare tags from all heads instead of just one Previously, the hg sink for puttags would just use one head for getting the old tags which would sometimes lead to tags disappearing. Now, we iterate over all heads and merge the results.

convert: add closemap option Tests have been updated.

convert: add parseclosemap method This is a copy of the parsesplicemap method and will serve as a way to specify which changesets to close while converting.

convert: add mapname parameter to checkrevformat Upcoming patches will add new map files so we change the calling sequence of checkrevformat so that error messages will let the user know which file has the wrong rev format.

convert: replace old sha1s in the description This is a simple find-and-replace strategy for matching anything in the old description of a converted commit and, if that matched sha1 exists in the mapping, replacing it with the new sha1. In particular, this is helpful for descriptions that contain tags with messages such as, "Added tag 1.0 for commit abcde1234567" which will now be automatically converted. Tests have been updated accordingly.