Bumped version to 2.7.1
As a part of the task T50726:
Update the Panel rename code to more generic one
Pep8 cleanup
Replace star imports
Consistent property definitions
Update wiki link
move the register of properties and collections
to register function, proper removal on unregister
Refactor the exporter as it assigned the operator
properties from the scene ones
cmp is deprecated in Python 3.x