Added DSM5.0 compatibility to several packages

Started with PR #818, and made some additional changes.
TT-RSS web interface and feed updates work, as well as package updates on DSM5.0 and DSM4.3.

Separate PR, as there might be better ideas. A similar approach should work for the other packages mentioned in PR #818.

/edit...for whatever reason, it doesn't update by itself on DSM4.3 it seems...need to check that out.