Pull request for Issue1034: XES Apply to scans issue

"Apply to scans" is working, but the fact that it writes directly to the db, which doesn't push those changes up to open scans continues to cause problems for users.

Added a confirmation dialog to try to clarify this to users.
For the controls, use the ```this``` pointer.  As an example, 
```imageControl_ = new AMReadOnlyPVControl("Memory Buffer", "PDTR0000-01:zippedBuffer", this);```