Fix strict mode

[dsferruzza]

Hi!

Because "user strict"; is outside of the closure, it seems to apply to everything. I have other dependencies in my project that breaks when minified together with ui-codemirror because of that.

I hope you will merge it and bump a new version soon. Have a nice day!

[whitehat101]

:+1: This PR is correct, "use strict" should be inside your module.

I bet this will also fix issue #39

[geyang]

Can we merge this one?

[magmel48]

+1