Tests for latest code ported from UI codebase

[mikesherov]

• drag options: x, y, handle
• drag simulating mousemove: document -> target.ownerDoucment
• drag element removed during drag: if ( $.contains( document, target ) ) {
• mouse event options: button value -1.

Commits:

• 44594dd
• dd3c930
• fce39f8
• 779bcef
• 386afd3