Support for approximated radius in physicalengine.

Added code to class Building and Border to support the changes.
Easier to add points to qaudtree.
Revert "Easier to add points to qaudtree."

This reverts commit c527375ff9600a8266598e043a0a8845d9d62138.
Merge branch 'master' of https://github.com/mwthinker/Zombie