Add support for multiple boards.
Add initial untested support for F4 Discovery.
Add support for multiple projects.

Compile "test" or "pleco" projects with the following commands:
SC_PROJECT=test SC_BOARD=SC_F4_DISCOVERY make
SC_PROJECT=pleco SC_BOARD=SC_SNOWCAP_V1 make

SC_PROJECT defaults to "test" if not specified.
Add initial untested support for F1 Discovery.
Add compile-all-test.sh

Run compile-all-test.sh when changing the framework to be sure no
application gets broken.
LED: typofix in comments.
Pleco: Fix compilation error with F1 Discovery.
Add GPIO API.
GPIO: Added initialisation.
GPIO: Add command parsing.

Add parsing of GPIO commands and Fix GPIO module implementation.
Pleco: Add 'not tested' note.
Add application for measuring FPS.

Use light sensor to measure FPS of a video showing sequential black
and white frames.