Fixed all warnings for examples.
[examples] added simple spi and dma based spi examples for stm32 f1 on Lisa/M v2 board
SPIEX: Fixed warnings in the new SPI examples.
Add a few example programs for the Leaf Maple / IteadMaple boards.
[examples] [maple] Fixed all warnings in the new leaf maple examples.
Implement SPI clean disable from TODO comment
[stm32] [lib] Fixed declaration of spi_clean_disable to match implementation.
Minor fixes to RTC definitions
Formatting and commenting

- No changes to content
- Lots of comments added
- Tabs --> spaces  and uniform spacing
Adding f4-specific rtc functions

These should also work with the f2
Adding some useful functions for wakeup timer interrupts