fix openxcplatform.com link on README
Made the speed, mpg, steering wheel angle, fuel, and odo thread safe.
fix vendor ID for FTDI chip to 1027. make sure GaugeDriverActivity only launches once.
Removed redundant USB permissions check, removed unused imports, removed unused
ACTION_USB_DEVICE_ATTACHED handler.
Fixed re-connection bug with multiple devices.  Now handles device disconnects
properly with multiple devices.
merge in master branch. fix conflicts.