Takes less time to print one tab than 4 spaces and a comma
Use multiplication for scaling sensors

- removes oddness of conversion to radians
- multiplication is faster at a hardware level
Tidy up of some global variables
rename led variables
Records binary data

After a run, plugging into a computer and running scripts/upload.py will pull the logs off the sd card and parse them into a csv file
Staggers pressure/temperature reads, shrinking loop times to 6ms
Merge pull request #4 from cuspaceflight/datalog-improvements

Datalog improvements