Support Old BoxCar CSV Files

[riggsd]

The old BoxCar Pro software produced a more limited CSV output than does HOBOWare. Consider adding seamless support for these files (which were likely produced in the old "hockey puck" H08 days).

I don't have access to BoxCar Pro anymore, but it looks like this may be an example of its default output with a HOBO H08:

Date Time	Temperature (*C) c:1	High-Res Temp (*C) c:1 2	RH (%) c:3
07/07/03 10:45:40.0	26.34	26.22	48.3
07/07/03 11:45:40.0	24.4	24.35	44.2
07/07/03 12:45:40.0	22.86	22.76	45.7
07/07/03 13:45:40.0	22.86	22.69	46.7