fix(input): setViewValue on compositionend

Because of a4e6d962, model is not updated on input/change between the 
compositionstart and compositionend events. Unfortunately, the compositionend 
event does not always happen prior to an input/change event.

This changeset calls the listener function to update the model after a 
compositionend event is received.

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http://plnkr.co/edit/euPnjrLk918G31aTDPjN?p=preview test-case which gives me adequate results on Nexus S

Fixes #5308, #5323