gvle: refactoring the Dynamics Editor Dialog

* A single treeview widget does provide all the editing features.
* Adding, Duplicating, Copying, Renaming is done directly inside the
  treeview
* A control has been added when editing the names.
* For the packages and the libraries, ComboBoxes are provided directly
  inside the cells.
gvle: fix the new project window title

We update the window title even when a new project is started.
(closes #47)
gvle: add a menu item to the dynamics treeview nenu

The contextual menu of the dynamics treeview of the atomic model box
dialog does provide an item to launch the conditions editor.
gvle: remove the model column of the dynamics list

The obsolete model column of the dynamics treeview tab of the atomic
model box dialog has been removed.
Merge pull request #49 from Chabrier/master

gvle: refactoring the Dynamics Editor Dialog