Another major cleanup. Have gotten rid of nearly all warnings (there are some that freeRTOS left because it's nastily inconsistent about signed vs. unsigned in certain places), and have factored out the interrupt latency, message queue, and checkpoint tests into different functions and surrounded them with ifdef guards. The interrupt latency and mq tests are mutually exclusive, and the checkpoint test will run the message queue test by default. These defines can be changed in src/components/include/jw_freertos.sh.