Revert "Adding zlib - working on MacOS"

This reverts commit 325296486cce944d65f306ef47ebacf886daa823.
Revert "Add libpng source to allow for easier intergration with node-webkit"

This reverts commit b2129d2336d80f10a63506d41322b59a96ea3e72.
Add files so it can be re-build using nw-gyp

Conflicts:
	package.json