galileo/GPS/GLONASS/BeiDou open source monitoring tools.

Highlights:
* Support for Septentrio and U-blox.
* Processes raw frames/strings/words from GPS, GLONASS, BeiDou and Galileo
* All-band support (E1, E5a, E5b, B1I, B2I, Glonass L1, Glonass L2, GPS L1C/A) so far.
* Calculate ephemeris positions
* Comparison of ephemerides to independent SP3 data to determine SISE
+ Globally, locally, worst user location
* Record discontinuities between subsequent ephemerides (in time and space)
* Compare doppler shift as reported by receiver with that expected from ephemeris
* Track atomic clock & report jumps
* Coverage maps (number of satellites >5, >10, >20 elevation)
* HDOP/VDOP/PDOP maps
* Compare orbit to TLE, match up to best matching satellite
* Tear out every bit that tells us how well an SV is doing
* Full almanac processing to see what should be transmitting
* Distributed receivers, combined into a single source of all messages
* Ready to detect/report spoofing/jamming