Add Bountysource badge to README

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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 branch 'master' of https://github.com/bjorn/tiled into mine-master