Resolve "Addon removal is ambigous"

Closes #37

See merge request !34

# Conflicts:
#	CHANGELOG.md

- Fix get_addons possibly altering addon_map and addon_filter_map
- Fix get_addons not locking addon mutex
- Make get_addons const
- Make other functions const corretct too

Fix windows dll build

See merge request !35

Resolve "Coverage doesn't include cpp files"

Closes #36

See merge request !33

Resolve "interface name collision with macro from "combaseapi.h""

Closes #35

See merge request !32

Resolve "update 2020 to 2021 in headers"

Closes #33

See merge request !31

Resolve "CI Error reporting broken"

Closes #34

See merge request !30

Resolve "pulley contract potential crash"

Closes #32

See merge request !28

The contract in pulley now makes suer the global r is initialized before the contract tries to register itself.

This is necessary since the initialization is unordered for static template members.