Internally regularily order the source files.

     Change: regular-ordered-sources
     Purpose: Internally regularily order the source files.
     Reason: RPM internally traverses over the list of source files
                     (SourceX and PatchX tags in *.spec file) multiple
                     times and also looks up sources by number. For all
                     this the fact that RPM keeps the source files in a
                     _reverse ordered_ linked list is never a problem.
                     But OpenPKG performs user-visible actions, like
                     the auto-fetching of still missing source files,
                     and here the processing in reverse order is very
                     confusing to the user. Hence, order the sources
                     files in regular order (the order the tags occur in
                     the *.spec file).