On branches tracking remotes, there would be two spaces between the last
character and the first character in the status part. On other branches,
there'd only be one. Make it so that there's only one space at all
times.
In the function calculating differences between local and remote
histories, an extra space was added before the first part, thus where
the second space came from. Remove that.
To make integrating with plugin managers as easy as possible,
plugins/scripts shouldn't be sourced on their own; instead, they should
export functions.
Split former `parse_git_status` function, which was around 60 lines of
code, into multiple small functions.
Also, instead of polluting the global namespace with a lot of variables,
make functions return something through a $REPLY variable. Or the
$STATUS variable, in the case of the *new* parse_git_status function.
