Sending ephemeris message
Unpacking ephemeris
Fixed ephemeris unpacking format
parsing ephemerides
pointing to new libswiftnav commit
Not using ephemeris callback in console
Formatting
Pointing to libswiftnav new master
Update solution filter.
Add release notes for v0.13, bump libswiftnav to v0.13
Modified serial_link.py to record SBP logging data.

serial_link.py can now log serialized, timestamped SBP messages to a
consistently-named logfile, but only if libsbp is available for
serialization.

r=@fnoble,@cbeighley

Closes #186.
Cleanup serializaton logger.

Moves log formatting (timestamps) into actual callback.
Saving ephemerises
More efficient saving of ephemerises
Missing slash
Merge pull request #194 from imh/master

Added ability to write out ephemerises
Bit of refactoring for SBP logging.

0. Added fallback SBP definition since libsbp isn't out yet and its
use here is completely superfluous.
1. Reverted msg_type callback interface.
Merge pull request #193 from mookerji/183-spectesting

Modified serial_link.py to record SBP logging data.
serial_link: get_message return type not updated for new format in one place
serial_link: add options to reset Piksi and exit after timeout