Code quality improvements for stick

• Bug-fix: Power history was not reported (0 value) during last week of the month
• Improvement: Validate message checksums
• Improvement: Do a single ping request to validate if node is on-line
• Improvement: Guard Scan sensitivity setting to medium
• Improvement: Move general module code of messages, nodes, connection to the init.py files.
• Improvement: Do proper timeout handling while sequence counter resets (once every 65532 messages)
• Improvement: Better code separation. All logic is in their designated files:
  1. Connection (connection/*.py)
  2. Data parsing (parser.py)
  3. Data encoding/decoding of message (messages/*.py)
  4. Message handling - Initialization & transportation (controller.py)
  5. Message processing - Do the required stuff (stick.py & nodes/*.py)
• Improvement: Resolves all flake8 comments

Fix sensor scaling

• Fix for via HA Core issue #44349
• Remove aiohttp-workaround - issue solved in aiohttp 3.7.1

Keep backwards compatibility

Merge pull request #47 from plugwise/passwdfix

Update changelog

Bug-fix, add model-info to output, code and test improvements

• Switch Smile to defusedxml from lxml (improving security)
• Lint and flake recommendations fixed
• Project CI changes
• Bug-fix: fix use of major due to change of using semver.VersionInfo.
• Add model-info: to be used in Core to provide a more correct model-name for each device.
• Code improvements and increase in test-coverage.

Standardize logging for stick

Merge pull request #22 from plugwise/release-0.8.1

Bump to v0.8.1

Merging Plugwise-Smile and python-plugwise

Plugwise-Smile (by @CoMPaTech and @bouwew) and python-plugwise (by @brefra) have been merged into plugwise, picking up and continuing the work done by @cyberjunky and other predecessors.