bookmarks: use "changectx.descendant()" for efficient descendant examination This patch uses "old.descendant(new)" expression instead of "new in old.descendants()" for efficiency.

context: add "descendant()" to changectx for efficient descendant examination This patch adds "descendant()", which uses "revlog.descendant()" for descendant examination, to changectx. This implementation is more efficient than "new in old.descendants()" expression, because: - "changectx.descendants()" creates temporary "changectx" objects, but "revlog.descendant()" doesn't "revlog.descendant()" checks only revision numbers of descendants. - "revlog.descendant()" stops scanning, when scanning of all revisions less than one of examination target is finished this can avoid useless scanning in "not descendant" case.

bookmarks: avoid redundant creation/assignment of "validdests" in "validdest()"

store: add a fallback _pathencode Python function which does the equivalent of parsers.pathencode, so it can be used as a default

store: move _plainhybridencode and _dothybridencode higher up in the file no functional change

test-hybridencode: use store._dothybridencode(s) and compare it with the result of store._hybridencode(s, True)

store: fix _hashencode call in _dothybridencode Fixes 7840d81a80ec

check-code: catch yield inside try/finally (with tests) This is not allowed in Python 2.4.

Merge with mpm

store: use native fncache encoding function if available This currently falls back to Python for hashed encoding.