Minimal version of mBuino Sleep
This is a cut down version of mBuino_Sleep that doesn't control any IO lines.
This version should work fine on any NXP LPC11Uxx CPUs although you will need to check the external pin pullup/down status, any conflicts between external and internal pulls will increase power usage.
If using this version on an mBuino ensure you disable the pullup on P0_3 (on by default for any unconfigured GPIO lines) and turn all the LEDs off before entering sleep. Failing to do so will increase the sleep mode power draw.
See mBuino_Sleep for usage details.