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)

localrepo: rename in-memory tag cache instance attributes (issue548). - self.tagscache to self._tags - self._tagstypecache to self._tagtypes - this is for consistency, readability, privacy, and to subtly hint that "caching" is something else

localrepo: factor _findtags() out of tags() (issue548). This makes in-memory caching the sole responsibility of localrepo, eliminating some localrepo code that was duplicated in mq and bookmarks.

test-tags: enhance the test to probe tag caching better (issue548). - give detailed dumps of .hgtags and localtags content - repeat some query operations to expose cache bugs - ensure that rollback/strip undo tagging operations

test-tags: clarify test output; simplify test script a bit (issue548). - use simpler way ('hg id') to get current changeset id - add 'echo' statements to guide the eye when reading output - add some more output to clarify the state of .hgtags - drop '-d' option from every commit/tag, since run-tests.py does this (although with a different timestamp, so changeset ids differ)

merge with crew-stable

Merge with crew-stable

Merge with crew-stable

Merge with crew-stable

merge with mpm