[WIP] GPIO refactoring

[WIP] Refactoring part #3

[WIP] Refactoring part #2

[WIP] Refactoring - separated platform and common code

[I2C] Refactoring

Serial support, MSP430 USCI UART

[MSP430] Updated and refactored USCI code

[MSP430/digital_io] Updated

[MSP430/timer] Define USE_EXTERNAL_CRYSTAL as 1 to enable external 32kHz crystal

Updated objdump options

[I2C] Fixed, start of the next refactoring

[BMP085] Fixed and updated to match I2C changes

[MSP430] Fixed Msp430_GetSupplyVoltage() function (strange values on the lower range)

Lightweight and universal *printf function. Supported tokens: %d, %u, %c, %x, %s, no other formatting yet

Simple FIFO queue