(HAL TI) Add external interrupt support for TI.
(HAL TI) Improve HAL I2C interface.
(ARDUINO) Fix string.h include.
(HAL ST) Add I2C support for STM32F0.
(HAL ST) Add elapsedMicros method.
(HAL ST) Add dummy Configure method for uart.
(ARDUINO) Improve arduino SPI frontend.
(ARDUINO) Refactoring arduino_serial which is now based on Print class.
(ARDUINO) Fix auto using namespace std in arduino frontend.
(ARDUINO) Add default arduino version to 100.
(HAL TI) Add timer support for TI.
(EXAMPLES) Fix includes in timer example.
(HAL ST) Adding stm32f4. Factoring stm32 hal.