Split up odometry node a little bit

preparation for writing a new odometry algorithm
WIP new odometry node
Some refactoring of odometry node

Split things up so common routines are in OdometryNode, create
LeastSquaresOdometryNode in anticipoation of more methods.
Split measurement recording

part that changes every time and part that depends only on the robot
(getPodPositions)
Add steering angles to measurement data structure
Make OdometryNode init function virtual
These files were the wrong approach, unneeded.
More work on EKF odometry

This version appears to produce smooth velocities.
Move data ostream printer to correct cpp file
Remove position from state and integrate in correct frame

This should really be handled by a non-linear system model, this will work for
now.
Add zero perpendicular measurement

Velocity measurement perpendiculator to wheel direction is zero.
Fix integration of orientation

forgot dt
Switch to EKF_odometry
Make pause_switch.py executable

so it can be run from devel.
Make image desync wait timer one shot

makes restarts more predictable
Phonetic spellings for some phrases
Wait a bit for system startup
Temporarily ignore manipulator cameras
Only change mode when needed

Mask off other GPIO bits
Split out machine definitions