EFM32, STM32, and STM32 F7 I2C:  Update to use the standard parameter passing to interrupt handlers.

STM32F0: Add some protection.  There is only one interrupt for USART3-8.  Current interrupt handling logic will support only one interrupt in that range.

I am not sure why spi.h is still generating warnings.  A few more parentheses and that seems to fix the problem

In last changed to poll(),cConverted timeout to unsigned to eliminate the possibility of overflow of signed overflow.