Fixed issues with USB keyboards. The USB keyboard functionality is memory mapped into a portion of low memory on some (maybe many) machines, typing on a USB keyboard changes some values in RAM as the key presses are stored in memory as you type. This can cause the keyboard to become unresponsive during testing or input from the keyboard to generate errors in the tests.
Fixed crash when configuring memory ranges. Changing the meory range during the first test, or changing the memory range multiple times during later tests could cause the current test number to become negative, triggering a crash.
Fixed highest error address not reporting correctly on error.
Fixed error counters overflowing and reseting to 0 after too many errors.
Fixed max contiguous error reporting.
Cleaned up some UI text.
The Windows USB package now includes ImageUSB to make creating Memtest86 USB drives easier.
