KeyProcessorSimulation extended to more preview events
ReSharperCommandTarget put in own file

This class needs to evolve quite a bit to allow for better R# testing.
Moving it to it's own file and making it internal to facilitate this
Increased the accuracy of keyboard simulation

The VS key processor should only be routing directly to IOleCommandData
for keys that bind to keyboard commands.  Items such as textual input
should be routed instead to normal keyboard processing