LPC11U35 support for USBDevice and mbed-rtos

Added support for the EA LPC11U35 QuickStart Board to USBDevice an
mbed-rtos. Also fixed several string-related bugs in USBDevice.
Merge pull request #146 from neilt6/master

LPC11U35 support for USBDevice and mbed-rtos
added toolchain uArm to STM32 target
Merge remote-tracking branch 'upstream/master'