Version 0.4.2 - Corrected Altitude and GPS Parsing

The GPS string parsing has been corrected.  In addition:
- there are timestamps of the system time that accompany each data point
- sail accepts time of flight information from the balloon, prints it,
and stores it in the datafile
- a new parameter allows you to input the default command
- the local versions of the program are now up to date and automatically
run with a 50 ms delay
- a multitude of bugs were fixed, mostly in the parser