Added getCoordinates

This function can now be used from every other custom module.
Add and Edit now use this function
Changelog updated
Comment updated
Optional removed and return moved
PSR-2-code-styling applied

Comments also removed
Merging master
Removed unneeded changelog line
Merge branch 'adding-BackendLocationModel--getCoordinates' of github.com:jeroendesloovere/forkcms into jeroendesloovere-adding-BackendLocationModel--getCoordinates

Conflicts:
	CHANGELOG.md
Merge branch 'jeroendesloovere-adding-BackendLocationModel--getCoordinates'