Remove duplicate declaration
Added more warning CFLAGS to all makefiles.
Fix all warnings for stm32f1 lib.
Fix all warnings for stm32f2 lib.
Fix all warnings for stm32f4 lib.
Fixed all warnings in stm32l1 lib.
Fix all remaining lib warnings.
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
Fixing some errors introduced with #107.

Namely:
 - I never added rtc to the makefile, so it wasn't getting compiled
 - I missed 2 includes that are needed once it's actually compiling
[stm32] Added *DECLS in stm32/common/gpio_common_all.h and stm32/l1/rcc.h