fix compile issue with system_lpc111x.c (analog power control function name)
Make HSE_Val optional in lpc11xx.mk
Fix UART header & IRQ echo example naming issues, compile issues.
Fix inconsistencies in gpio.h header.
Fix consistency issues with iocon.h header.
Change default build to LPC1114/201 for examples.
Examples are small; they will run on the /301 chip even if compiled for
/201.
Change default optimization level to debug (-g) in lpc11xx.mk