Add option to allow for drawing into active layer

Hi,

This commit adds the ability to draw into the current active layer. Active layer can be changed while dialog is open.  Ability to draw into memory layer is retained.

The following changes have been made:

- Add option to allow for drawing into active layer
- Update active layer text on active layer change
- Remove unndeed layer edit calls. provider.addFeatures will bypass layer edit buffer
- Bump version, update change log

Completed by Digital Mapping Solutions, Australia

Should fix part of #4