cleanup: reuse existing wctx variables instead of calling repo[None] Incidentally, this apparently means we load .hgsub one time less as well, which affects a test case.

localrepo: extract bookmarkheads method to bookmarks.py This method is only used internally by destutil, and it's obscure enough I'm willing to just move it without a deprecation warning, especially since the new method has more constrained functionality. Design-wise I'd also like to get active bookmark handling folded into the bookmark store, so that we don't squirrel away an extra attribute for the active bookmark on the repository object.