[NUCLEO_F030R8] Many improvements added

- Automatic clock configuration at startup between HSE and HSI
- System clock = 48 MHz for both
- Configure LSE for RTC (if not available LSI is used instead)
- Add 1MHz clock for I2C
- Update SPI prescaler values
- Typo corrections
Merge pull request #271 from bcostm/master

[NUCLEO_F030R8] Many improvements added
[NUCLEO_F030R8] Replace include of stm32f0xx.h with cmsis.h
[NUCLEO_F302R8] Move back SetSysClock() call in SystemInit()

The serial_init() function is called before the mbed_sdk_init() (I don't
know why?) and this causes an incorrect baudrate calculation.
[NUCLEO_F030R8] Move back SetSysClock() call in SystemInit()
[NUCLEO_F103RB] Many improvements

- Add more USART, SPI, I2C, PWM and AnalogIn pins
- Use TIM4 instead of TIM1 for the ticker
Merge pull request #272 from bcostm/master

[NUCLEO_F030R8/F302R8] Move back SetSysClock() call in SystemInit()