bookmarks: add invalidate() to bookmark_repo
Cached bookmark information would not be reset when repo.invalidate()
was called, meaning (for instanced) guis would be left with out-of-date
bookmark info. This patch fixes that by overriding bookmark_repo.invalidate()
branch: help misuse of hg branch to switch branches
Maybe beginners tend to use 'hg branch EXISTING_BRANCH' instead of
'hg update EXISTING_BRANCH' as me.
If so, let's help them to use 'update'.
Also removed '(use --force to override)' because it can mislead them.
Added signature for changeset
ff2704a8ded3