Added initial working ADC code with debug harness
Working ADC code.
Merge branch 'dev' into feature-power-management

Pulling build system changes into feature branch
Added debug functionality to adc module and verified functionality.  Removed 10 second heartbeat from reset_manager to avoid further annoyance
Began adding scheduling features to rtcc
Merge branch 'tmp-batt-management' into feature-power-management
Began to implement complete rtcc scheduling logic
Made project compile without -Os because it breaks the serial code
Added modular schedular to allow callbacks every 0.5, 1, and 10 seconds as well as 1, 10 minutes, every hour and every day. This will be the basis of the solar charging logic as well as the gsm logic and possibly many other housekeeping tasks as well
Scheduler module is working.
Battery charging feature is working.  It checks the battery voltage every 10 seconds and stops charging when the voltage is above
4.15V.  It restarts charging when the voltage falls below 4.0V.
Fixed uart errors.  volatile was not properly specified on some extern declarations for command handling related variables.
Also, fixed a latent bug in sendf that made it not completely synchronous.
Fixed reset_handler to actually return the correct reset types and implemented handlers for power_on and mclr resets.
Made the RTCC run always since it is required for the scheduler module to work.
Made the debug uart only wake for between 10 and 20 seconds following an MCLR reset.  If a command is not received in that time,
the module is completely disabled to save power.
Cosmetic changes
Moved scheduler to core
Merge branch 'feature-power-management' into dev

Power management features working as well as scheduler code and fixes the uart code as describe in commit messages.
Cosmetic changes
Merge remote-tracking branch 'origin/dev' into feature-sensor-acquisition

Conflicts:
	mainboard-firmware/project.yml
	mainboard-firmware/src/core/common.h
	mainboard-firmware/src/core/reset_manager.c
	mainboard-firmware/src/debug/command_handlers.c
	mainboard-firmware/src/debug/serial_commands.c
	mainboard-firmware/src/main.c
	mainboard-firmware/src/modules/rtcc.c