Consolidate things into a single View

* AndiconView is no longer abstract
    - All the child view classes are now "Sets"
* Introduce custom XML properties 'andicon_id' and 'andicon_set'
* Painstakingly refactored the various id resources into ints

Signed-off-by: Eddie Ringle <eddie@eringle.net>
Update README.md with new way of doing things

Signed-off-by: Eddie Ringle <eddie@eringle.net>