Wrappers for LAMBDA functions.
added files for UD kalman filter
using full UDU class
using C observation updates
added struct for KF
using kf struct throughout
added C transition matrix
added C D mtx
added C e mtx
added C DE mtx
added C obs_mtx
most of the KF generating functions in C now
added least sq initialization and KF constructor
using single diff objects
make filter management object
adding new dgnss control flow
tracking new files
new fields in kf struct
Merge branch 'master' into kalman

Conflicts:
	swiftnav/track.pyx
	swiftnav/track_c.pxd
fixed dimension of kf.decor_obs_mtx