When getting signals from higher level toolkits, occasionally
one wants access to the underlying event; say for a Button
widget's "clicked" signal, to get the keyboard state.
Rather than having all of the highlevel widgets emit
ClutterEvent just for the more unusual use cases,
add a global function to access the event state.
http://bugzilla.openedhand.com/show_bug.cgi?id=1888
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>