Aten iKVM support

Tested over multiple Supermicro boards (as detailed in the sourcecode) but with the most recent offereing from Supermicro I still need to reverse engineer their new encoding.  This code is good to go though and was tested with a regular local TightVNC to make sure I did not poouch the RGB<->BGR stuff in the Pixel Format work I had to do first.

This solves https://github.com/kanaka/noVNC/issues/385 and should start helping out for the work needed in https://github.com/kanaka/noVNC/issues/396

One gotcha, IE now much be version 10+ due to the pixel endian handling.
avoid use of objects for performance reasons