* It's now implicitly shared, meaning that changes to the config
can be supervised and a signal is sent from QgsVectorLayer and
there is no risk of elements suddenly being deleted.
* Remove a bunch of methods that were in QgsVectorLayer for legacy
reasons.
Do not rely on the presence of a dot to load
a module. Loading a module can now be achieved
through the code editor in the dialog.
* added an option to load from environment
* added a file selector to specify the file
* changed tooltips accordingly
