Removed TODO about optimizing has_many sort
Better handling of error if the sort column cannot be found in model classes db fields
Added issues and installer name to composer config
changed installer name to lowercase
Setup travis support
Allow PGSQL and SQLLITE to fail on 3.1
Fixed issue #33 were in newer browsers after dropping on the pagination arrows the edit screen would be displayed
Resolved issue #33 when sorting to page the to page sort was called first then the on page sort was called which caused the indexes to become confused
Merge commit '4de269e53f5d3c313142d5d21c5c7ada314fa5ca'

Conflicts:
	javascript/GridFieldSortableRows.js - used theirs