OpenPicoRTOS v1.9.0

[jnaulet]

This is a major revision that brings up a brand new graphical configuration menu (GUI), heavily inspired by the Linux/U-boot/Buildroot "make menuconfig".

OpenPicoRTOS is now more than an OS. It is an OS AND a build system AND a code checking system, too.

Migrating to OpenPicoRTOS has been made easier than ever (hopefully).

Some changes have been made to the port API & the main API, especially regarding asserts, that have been made ISO-C compliant to accomodate for the now default gcc -pedantic mode.

Cross-dependencies between the ports and the schedulers have been totally removed.

All drivers have benn migrated already & some have been improved, especially the SAM3x/Arduino Due I2C &
CAN.

Some work still needs to be done on the PowerPC chips, as we are still waiting for some replacements after the last ones have been stolen.