Actually attach/remove functions to mousemove. #2.

Minor 'bug fix' as intended code did not match what actually happening.
Code behaviour seems to work without the mousemove handler at all,
but I've left the originally intended logic for good measure.
Add naive removal function to return value. #2.

At least it disables the functionality. Further inspection
required to find possible memory leaks.
Add built files for your convenience. #2.
Merge pull request #3 from timoxley/feature/removal

Feature/removal