graphlog: refactor revset() to return revisions
When --follow and --rev are passed, --follow actual behaviour depends on the
input revision sequence defined by --rev. If --rev is not passed, the default
revision sequence depends on the presence of --follow. It means the revision
sequence generation is part of log logic and must be wrapped. The issue
described above is fixed in following patches.
$ hg init dir
$ cd dir
$ echo bleh > bar
$ hg add bar
$ hg ci -m 'add bar'
$ hg cp bar foo
$ echo >> bar
$ hg ci -m 'cp bar foo; change bar'
$ hg debugrename foo
foo renamed from bar:26d3ca0dfd18e44d796b564e38dd173c9668d3a9
$ hg debugindex bar
rev offset length base linkrev nodeid p1 p2
0 0 6 0 0 26d3ca0dfd18 000000000000 000000000000
1 6 7 1 1 d267bddd54f7 26d3ca0dfd18 000000000000