Added ignore categories option. This prevents SABConnect++ from sending ...

...the categories to SABNzbd and instead lets SABNzbd rely on the group fields in the actual NZB. Default is disabled so everything will work as before.

This provides much easier auto-categorization for many sites such as nzbindex and binsearch. Some sites (newznab at least) embed category information in NZBs, so SABnzbd still won't fall back to group names. This made things world's easier for me, but it's up to you if you want to include it.