Merge pull request #640 from Kienz/groupFix

Remove `fabric.Group.containsPoint`; it now uses `fabric.Object.containsPoint`
Build distribution
Make travis build distribution before running tests
Remove space at the bottom of containing box on text objects (with high line height). Fix underline/strike-through to work with line height correctly. Closes #608
Merge remote-tracking branch 'origins/master' into sketch