Add Bountysource badge to README

Because you have some open bounties, we thought you might want to display this badge in your README!
Fixed automapping object region check.
Merge pull request #697 from Roflraging/objectautomappingfix

Fixed automapping object region check
Merge pull request #685 from bountysource-support/patch-1

Add Bountysource badge to README
Added Travis CI badge
Prettier Travis CI badge
Merge remote-tracking branch 'upstream/master' into sjtiled