Add sampler names to ShaderData declarations necesary for OpenGL.

ShaderData changes:
* OGLVertexShaderFile/OGLPixelShaderFile not used in DX9.
* samplerNames[?] not used in DX9.
Merge pull request #611 from BeamNG/templates_shader_data_decl

Add sampler names to Templates ShaderData declarations necesary for OpenGL.