convert: change default for git rename detection to 50%
This default mirrors the default for 'git diff'. Other commands have slightly
different defaults -- for example, the move/copy detection for 'git blame'
assumes that a hunk is moved if more than 40 alphanumeric characters are the
same, or copied if more than 20 alphanumeric characters are the same. 50% seems
to be the most common default, though.
$ rm -rf a
$ hg init a
$ cd a
$ echo a > a
$ hg ci -Am0
adding a
$ hg tag t1 # 1
$ hg tag --remove t1 # 2
$ hg co 1
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg tag -f -r0 t1
$ hg tags
tip 3:a49829c4fc11
t1 0:f7b1eb17ad24
$ cd ..