Gui 1333 add warning when copying object onto itself.

https://eucalyptus.atlassian.net/browse/GUI-1333
I originally coded this with angular.forEach. The problem is that that runs async, so regardless of check and return happening inside, the subsequent code is executed. I saw my dialog display AND the http POST happen anyway. That's obviously not desired, so I had to revert to the for loop which executes in-line.