* Cleaned up the build, somewhat.
* Now building against GCC w/ newlib instead of glibc.
* Added a heap section to the linker script to anticipate newlib syscalls.
* Added heap to memory layout.
* Populated NVIC ISR vector.
* Cleaned up RCC code a little (Still WIP).
* Improved abstraction in the GPIO module.
* Added LED abstraction on top of relevant GPIO pins.