Reverted use of submodules

Reverted use of submodules for OpenP2PNet and updated OpenP2PNet to commit 4f0aab96f6700d6413a1020227b2d396c0e41173
Multiple fixes

-Updated OpenP2PNet to 3c0c2a14b7a9a3e353935202d27af9c2243b1c51 and fixed implementation
-Added ground overlay under bomb
-Tiny other fixes
Merge pull request #20 from rtydev-shared/master

Implementation fix of OpenP2PNet