localrepo: improve readability of _findtags(), readtags() (
issue548).
- rename many local variables
- add some comments
- refactor call to line.split() (catch ValueError rather
than checking length of return value: one less local variable)
#!/bin/sh
rm -rf a
hg init a
cd a
echo a > a
hg ci -Am0
hg tag t1 # 1
hg tag --remove t1 # 2
hg co 1
hg tag -r0 t1
hg tags