Each effect item now exposes a ListModel property which describes the
set of user-controllable parameters. This model is used by the
ParameterPanel component to generate a ListView whose delegate displays
the parameter name and a slider.
Change-Id: Ib26877fe434d8b746ef621e0b4adbcbe1ed9aaa8
Reviewed-by: Michael Goddard <michael.goddard@nokia.com>