verify: lots of refactoring...
verify: lots of refactoring
- simplify finding first bad rev
- no need to count changesets
- add exc function to simplify exception handling
- combine checksize and checkversion to checklog
- unify missing revlog detection in checklog
- add checkentry to consolidate
- linkrev lookup
- detailed check of linkrev
- detailed check of parents
- duplicate checking
- use checkentry for changelog, manifest, and files
- simplify havecl and havemf
- track all changesets refering to a manifest
- move unnamed file check somewhere more useful
- reorder crosschecks
- fix filenodes crosscheck and add exception handling
- check unpacked size field