Fix potential problem with timestamps in RSS.
Prevent folder trimming from removing embedded passwords in filenames.

Reduce the number of calls to sanitize_foldername() and rely on NzbObject to do its work.
Also allow "oversized" incomplete folders to be sent back to the queue, by not sanitizing/trimming again.
OSX Signing is now only possible on OSX Mavericks, so check this.
Update text files for 0.7.19RC2
Merge remote-tracking branch 'upstream/0.7.x' into 0.7.x