util.h: Utility macros for handling different Python APIs. If we are in py3k, a IS_PY3K symbol is defined. Apart from that, byte strings use the API defined in Python 2.6+ (_?PyBytes_.*). For Python < 2.6, the bytes API is defined accordingly for mercurial usage (shameless copy from bytesobject.h from Python's code). Some macros were backported from 2.6, as inspired by rPath's pycompat.h.

relink: ensure deterministic directory walk in collect

help: add "glossary" topic Joint work with Vishakh Harikumar, Pradeepkumar Gayam, David Champion, Mark Booth, timeless, Matt Mackall, Heinrik Stuart, Greg Ward, and Martin Geisler.

relink/progress: Adding progress for collecting stage

relink/progress: Adding progress for pruning stage

merge: when current branch has 1 or > 2 heads, actually abort. Currently merge just prints abort-like messages to stderr and then exits with a misleading status 0 (cleverly disguised as "False"). With this change it raises Abort, just like every other fatal error.

tags: remove inactive debugging code. It was left in just in case things went wrong with the tag cache in Mercurial 1.4, so we could easily crank up the verbosity with a one-line change. There have been no problems in 1.4 or 1.5, so it should be safe to drop this now.

tags: remove the old non-caching implementation of findglobaltags(). It was left behind just in case the tag cache blew up in Mercurial 1.4, so we could easily revert to the non-caching code. There have been no problems with the tag cache in 1.4 or 1.5, so it should be safe to get rid of this code now.