Examples updated to use new rcc_periph_clock_enable function
Correct include path in all examples
[DOC] Updated README's for F0 and F4 examples to describe the needed board connections.
[STM32F0] Stylecheck

There are remaining C99 comments.
[STM32F4] Stylecheck

Some style errors couldn't be resolved in this commit
[STM32L1] Stylecheck