tag: handle .hgtags and .hg/localtags with missing final newline (issue 601)
This also fixes an asymmetry bug in which we called the pretag hook if we
were going to create a local tag, but didn't call the tag hook afterwards.
#!/bin/sh
hg init
echo a > a
hg ci -Am t
hg mv a b
hg ci -Am t1
hg debugrename b
hg mv b a
hg ci -Am t2
hg debugrename a
echo % test with --rev
hg debugrename --rev 1 b