Fixed the conflict with panning mode and graphical addition operation.
Workaround for slow editing function code. Disabled the automatic syntax
highlighting. (issue #443)

Minor fix on reverse engineering process. In some cases the process was
aborted due to duplication of relationships caused by an incorreclty
name generation for this kind of object.

Minor fix on model objects widget when changing the visible object
types.
Minor change on project's description text on about dialog.