add: use lexists so that broken symbolic links are added This restores the add behavior prior to d8cdd46f426d and matches the behavior of addremove.

rebase: avoid redundant repo[rev].rev() - just keep working in rev space

rebase: always store rev in state, also when collapsing

rebase: clarify naming of variables holding node hashes - don't call them rev

bookmarks: factor out bookmark file opening for easier extensibility

merge with stable

diff: explicitly honor all diffopts 'hg diff' should naturally honor all diffopts.

annotate: explicitly only honor whitespace diffopts The whitespace ones are the only ones the annotate logic cares about anyway, so there's no visible impact.

notify: explicitly honor all diffopts The notify output doesn't seem to be parseable anyway, what with the maxdiff config option. Plus it is designed mainly for servers where hopefully the admins are doing sensible things.

jsonchangeset: don't honor whitespace and format-changing diffopts JSON is meant to be parsed by computers, and format changes can break them.