Pytak

Happy Summer Solstice

- Fixes 72: Add a config variable for users to set expected CN when using CA verification. Thanks ahoenerBE
- Added configuration parameter: PYTAK_TLS_SERVER_EXPECTED_HOSTNAME
- Rewrote GitHub actions, moved most logic to shell script and Makefile.
- Renamed Debian package from python3-pytak to pytak.
- Standardized Makefile for all PyTAK based programs.
- Cleaned, simplified and expanded documentation.
- Created Makefile jobs for Debian packaging and PyTAK customization.
- Moved all media to media sub directory under docs/.
- Converted README.rst to README.md.
- Style & Linting of code.
- Refactored TLS client creation, abstracted many functions.
- Added TLS client cert and key checks and improved error messages.

- Fixes 69: PyTAK's TAK_PROTO=1 doesn't always work with iTAK.

- Fixes 67: Add constrained logging for systemd invocation.

- Fixes 58: TypeError: can't multiply sequence by non-int of type 'float'.
- Fixes 64 (?): Cryptography functions deprecated
- Fixes 65: Performance issues with large queues, sleep only on empty queue.
- Fixes 66: Add config params MAX_OUT_QUEUE & MAX_IN_QUEUE to allow queue tuning.

- Fixes 63: Python 3.6: AttributeError: module 'asyncio' has no attribute 'exceptions'.

- Add 'PEM pass phrase' prompt instructions. Fixes 54.