Improve the 'parents' parsing for git and ignore any empty parts; also

react gracefully if we could not parse the parents for some weird reason.

NEWS.mdtext

@@ -37,6 +37,8 @@ or newer to properly run this version of Indefero!
   and only display this list if there are any branches available for all SCMs
 - If git's author name is not encoded in an UTF-8 compatible encoding, skip the author lookup,
   as we have no information what the author string is actually encoded in
+- Indefero no longer displays an empty parents paragraph in the commit view for root revisions of
+  a git repository
 
 ## Documentation