Thingsquare MSPsim additions

A bunch of things:

* Emulation support for a bunch of new chips: TI CC1101, TI CC1120, TI CC430, Microchip ENC26J80
* Emulation support for a bunch of new boards: TI MSP430 experimenter's board with the CC1101 and the CC2520, TI TRXeb with CC1120
* A few smaller bugfixes and improvements