minimal reStructuredText parser

util: wrap at termwidth-2 by default

Merge with stable

Add ui.progress API

tags: support 'instant' tag retrieval (issue548) - modify _readtagcache() and _writetagcache() to read/write tag->node mapping for global tags - if (and only if) tip unchanged, use that cached mapping to avoid reading any revisions of .hgtags - change so tag names are UTF-8 in memory in tags.py, and converted to local encoding as late as possible (in localrepository._findtags())

tags: implement persistent tag caching (issue548). - rename findglobaltags() to findglobaltags1() (so the "no cache" implementation is still there if we need it) - add findglobaltags2() and make findglobaltags() an alias for it (disabling tag caching is a one-line patch) - factor out tagcache class with methods readcache() and writecache(); the expensive part of tag finding (iterate over heads and find .hgtags filenode) is now in tagcache.readcache()

localrepo: add destroyed() method for strip/rollback to use (issue548).

Factor tags module out of localrepo (issue548). Currently only handles reading tags, and will soon grow support for tag caching. Could eventually deal with updating tags too.

localrepo: factor updatetags() out of readtags() (issue548).

localrepo: improve readability of _findtags(), readtags() (issue548). - rename many local variables - add some comments - refactor call to line.split() (catch ValueError rather than checking length of return value: one less local variable)