Fixed tree_lock method to make left side div and tree dim when in edit.

- Fixed locking of tree and make it appear dim, this broke during dynatree conversion.
- Changed opacity in css for class that's being used when disabling the tree.
- Added code for ops/automate/vm/pxe/service/chargeback explorers to make tree div dim on a form screen.
Merge pull request #39 from h-kataria/miq_dim_div_fix

Fixed tree_lock method to make left side div and tree dim when in edit.