Removed ModelCacheSource.
Removed namespace prefixes from typenames for displaying to the user.

Fixes #389.
Fixed various PlugValueWidget setHighlighted() implementations.

They were all failing to call the base class implementation first.
Added blinking indication for plugs preventing the opening of a colour picker.

Fixes #185.
Merge pull request #390 from johnhaddon/modelCacheRemoval

Removed ModelCacheSource.
Merge pull request #391 from johnhaddon/typenamePrefixRemoval

Removed namespace prefixes from typenames for displaying to the user.
Merge pull request #392 from johnhaddon/nonEditableColorPlugs

Blinking colour widgets