Pycayennelpp

This release adds LppUtil providing a helper function for proper JSON encoding of PyCayenneLPP data objects, i.e. LppFrame, LppData, and LppType.

This release ships a new utility function to filter the data list of an LppFrame by name of the data type. For example you can retrieve a list of all temperature values in a frame by calling `frame.get_by_name("temperature")`.

This release ships with many more data types to keep up with popular Cayenne LPP libraries for other languages. It also includes some internal optimizations and code cleanup.

This release ships many internal changes and fixes, which improve data handling and ease future extensions of PyCayenneLPP. This goes along with several changes to the API, though the actual user (or developer) facing interface got only minor tweaks. Also by removing the base64 dependency and logging output PyCayenneLPP avoids special handling and is now natively supported by MicroPython.

This release again ships with more data types, namely support for generic 4 bytes values and unix timestamps. Further this release brings several improvements to the source code specifically addressing code deduplication.

This release adds two new data types namely Voltage and Load (weight).
Some minor fixes and improvements to documentation are includes as well.