Expand IMDB automation provider to include charts

Expand IMDB automation provider to include certain top charts, this
includes the 'in theaters' list, as well as the top 250 list. They both
respect the minimum requirement settings.
XBMC: Only scan the new movie folder
XBMC: Only add directory if XBMC is on localhost
Unset the uTorrent read only flags

Fix for #1871

Note that this is a fix for Windows only. I am unaware if this issue
arises on Linux/Mac and what happens with this fix on those systems.
uTorrent ratio issue fixed

The tryFloat function returns 0 if it is fed with a float(!). This resulted in the seed_ratio being set to 0 on first/automatic download. When manually downloading, it did work as the ratio is stored as a string.
Adding code for custom urls UI
Adding more code.
Revert "Adding more code."

This reverts commit 3a8f891c7d168d570b1c02ac51ebe00ebef34604.
Added custom url code handling
Changed description to be better suited for this.
Fix NZBGet url issue
Made code more python-y per mano3ms recommendation.
XBMC: properly check if host is local

And added option to scan if remote
Don't autoadd when already in wanted
Regard torrents and torrent_magnet the same

When sorting the torrents and torrent_magnets were sorted, by taking
only the three first characters (as 'nzb; is three chars), the score
prevails. Fixes #2004
Added initial rtorrent downloader, currently testing, possibly has some bugs.
Updated rtorrent-python library.
Added missing 'folder' parameter on the rtorrent downloader to fix moving/linking issues.
Added support for labels on the rtorrent downloader.
Cleaned up imports and added support for downloading magnet torrents via sources.