Python 3.10 compaibility + varius example stuff

fix title meta tag

Fixed setup.py to include subpackage

• Major code refactoring
• Minor speed optimizations
• TempyPage Fix

Resolves a problem of the init method that used to be executed 2 times, expecially with Python3.5 for some reason.

IMPORTANT: this is a backward-incompatible release if you use self._data in templates.
self.content_data completely substitutes self._data.

see the changelog for details