Python3 shebang fixes.
Make if-statement more Pythonic.
Fix transmission parameter checking.

The scaling isn't necessary to do here, since the fieldInfo.bounds values have already
been scaled.
Track the type of CAN message received.
Simplify code by having CANacondaMessageParse() just return the object.

There's no reason to create an empty object and pass it to the function when it can
just return it. Passing data around in Python doesn't follow from the way C does it.
Make unknown message names prettier.

Use the new message type data to indicate what type of message they are.
Remove trailing whitespace.

Once there's no trailing whitespace in a file, Git will show new whitespace errors in red,
so be sure to fix them before committing.
Don't repopulate transmission fields with converted value.

This makes it harder to slightly alter the values for another transmit.
Correct number conversion.
Documentation fixes.
Minor refactoring.
Fix transmission field-packing errors.

There were issues with both endianness and also selecting the proper bit-length of the field.

With this commit, transmission is now correct as far as I've been able to test.
Merge pull request #57 from Susurrus/master

Python3 shebang fixes.