parsers: use bitmask type consistently in find_gca_candidates Normalized type usage in find_gca_candidates triggered by warning from Microsoft Visual C++ 2008.

revert: drop `lexist` check in the backup logic We are no longer trying to backup files that do not exist on disk. This check can be safely dropped.

revert: distinguish between deleted file and locally modified Locally modified needs a backup while a deleted file cannot be backed up because there is no file to backup.

revert: detect unknown files in the same path as files marked as removed Such unknown files may need to be backed up. Having them identified beforehand will help simplify the backup logic. We now use different sets with different backup strategies.

revert: cache working context in a variable During the silicon age, humans on planet Earth discovered the use of variables. This marvelous invention let them improve both code readability and performance.

obsolete: properly drop 'date' from metadata Mistakes were made while resolving rebase conflicts in 4bc96685a40c. This led to 'date' being preserved in metadata when reading markers from a binary stream. As a result, some known markers were seen as "new" when pulling. I noticed it because a no-op pulls from main added about 600 duplicated markers to my obsstore (for each pull). I do not believe we need to perform any specific action to actively de-duplicates existing obsstore. After this fix, duplicated markers will no be propagated and the few affected repositories can probably deal with duplication (or people can repull the obsstore from a clone). As a side effect, we decode metadata only once, reducing the impact of the hack in fm0 to store extra important data (parents and date).

templater: implement __len__ for _hybrid Objects of class _hybrid are returned by such template keywords as children, bookmarks, tags and others, and also by revset() template function. They are representing "list of strings" (as hg help template says) for use in templates. So it would be logical to implement a handy way to count the number of strings in such list, and that's what __len__ method does.