Change xbmcnightlybuilds to point to mirror site.
Downloads will now automatically be redirected to nearest mirror
Merge pull request #1 from prae5/master

Change xbmcnightlybuilds to point to mirror site.
Bumped version
Merged prae5 changes from PR #2.
 - Rename xbmcnightlybuilds to XBMCNightlyBuilds (Nightly Builds)
 - Add XBMCNightlyBuilds Official Stable Mirror
Updated the Official Daily Builds url to snapshots.openelec.tv
Made XBMCNightlyBuilds (Nightly Builds) the default source.
Bumped version.
ATV uses MACH_KERNEL not KERNEL
Bumped version.
Use requests2 for retrieving build lists as this seems to handle the Accept-encoding issue
Housekeeping
Forgot to remove the header from the download request.
Changed wording of the set build type option.
Catch requests exceptions and handle response codes such as 404.
Bumped version
Fixed a problem retrieving the official release dates from github
Renamed 'Official Daily Builds' to 'Official Snapshot Builds'
Simplified the official release code now that a listing is available at releases.openelec.tv
Bumped version to 2.19.0
XBMC Backup changed the parameter to trigger a backup