Adapt tlc594x driver for using multiple channels.
Fix misuse of ALWAYS_INLINE in atmega::SpiMaster.
Rewrite UI led drivers using virtual functions and adapt examples.
Merge branch 'develop' into feature/multiple_output_tlc594x
Add isRunning() method to LED classes.
Fix double indicator stopping in first flash.
Merge branch 'feature/multiple_output_tlc594x' into develop
usart in spi mode for stm32f4

due to inverse bit ordering of usart sent and received byte has to be
bitinverted.

there should be no constructor for spi drivers static members are
desired.

split for the code definition the macro apbClockDefinitions from
pinDefinitions
Merge remote-tracking branch 'origin/develop' into feature/TCS3414-driver