Adding support for defining a description for a user POU type, and displaying this information in library tree.
Adding support for displaying a tooltip containing the informations of a function block when passing mouse over it in a graphic editor.

To generate message.pot file:

	python mki18n.py -p --domain=PLCOpenEditor
	
To generate .mo files for all languages:

	python mki18n.py -m --moTarget=../locale --domain=PLCOpenEditor