Clean up whitespace and JSHint issues after recent post-2.2 merges

Remember, !(0/0) is true as is !0, !(""), and !(undefined).

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@lge.com)
Add destroy method to ImageView to make sure bufferimage event handlers go away.
Fix logic in Panels.js where controls were only removed during panel destruction instead of intended case of removing them while it's alive.

Enyo-DCO-1.1-Signed-Off-By: Ben Combee (ben.combee@lge.com)
Merge pull request #12 from enyojs/2.3-layout-fixes

2.3 layout fixes