Merge pull request #1240 from seanpaultaylor/next

Fixes libpng error in newproject script for Linux
Copy the shaders folder using an absolute path
Merge pull request #1241 from rlofc/next

Copy the shaders folder using an absolute path
Changed the mesh and lua samples to load from a scene file.
Changed GP_ERROR on windows so that it will break properly when in debug mode.
Changed Material::create to return NULL if there is an error instead of failing hard. Also fixes loading a GPB with unused materials.
Merge branch 'next' of https://github.com/blackberry/GamePlay into next
Merge pull request #1242 from dgough/next

Changed mesh and lua samples to load from a scene file
Samples cleanup of Visual Studio 2013.