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.

% basic
% unknown
*** [alias] unknown: command bargle is unknown
% ambiguous
*** [alias] ambiguous: command s is ambiguous
% recursive
*** [alias] recursive: circular dependency on recursive
adding foo
% with opts
C foo