Allow the seamless removal of both paint and mappings.
Enable/disable creation of mappings depending on whether a paint is selected.
Added dialog when deleting paint.
Small change (cosmetic / performance)
Bug fix in the iteration over ids (was iterating over vector index, not item uids).
Methods removeCurrent*() reset uids to NULL_UID.
Bug fix: once all mappings were destroyed, current ids were not reset (removed).
Created a method addPaintId similar to the addMappingId to reuse some code.
Properly manage the windowModified() calls to let the software know something has changed.
Cosmetic change.