Various fixes and feature adds

Fixes:
* Cleaned up custom mode enumeration in Status message
* Re-aligned enum dictionary in ACS module
* Simplified ROS subscriber callback wrapper
* Replaced some print's with exceptions

Features:
* Added ability to pass ROS publisher optional args in get_ros_pub()
* Added ability to pass ROS subscriber optional args in add_ros_sub_event()
* Added 'mode_num' topic to ACS module to use numeric modes from enum
* Added 'calpress' topic to ACS module to perform barometric callibration