Logging

[ottopasuuna]

Adds logging support to the rover software. Instead of printing you call: self.log("Message", "DEBUG") where "DEBUG" can be replaced with any level defined in the python logging module (INFO is the default).

List of changes:

• RoverProcess gets a self.log(message, level) method
• Most print statements are updated to use self.log instead
• Log messages are printed to the console and written to a file. (This could lead to bad i/o performance if too many things are writing to the log file too quickly)

Closes issue #49 .

[LiamBindle]

I took a look over it @ottopasuuna . Love it!