git_commit() and git_tag() no longer prettify the
message by default. This has to be taken care of
by the caller.
This has the nice side effect of putting the
caller in position to actually choose to strip
the comments or not.
'git commit' and 'git tag -a' enforce some conventions, like cleaning up excess whitespace and making sure that the last line ends with a '\n'. This fix replicates this behavior.
Fixlibgit2/libgit2sharp#117
