GLProgram result in memory leak

[shinepengwei]

In luaTest/OpenGLTest.lua，the sample function createShaderRetroEffect use GLProgram as

local program = cc.GLProgram:create("Shaders/example_ColorBars.vsh", "Shaders/example_ColorBars.fsh")
        program:bindAttribLocation(cc.ATTRIBUTE_NAME_POSITION, cc.VERTEX_ATTRIB_POSITION) 
        program:bindAttribLocation(cc.ATTRIBUTE_NAME_TEX_COORD, cc.VERTEX_ATTRIB_TEX_COORD)
label:setGLProgram( program )

Use GLProgram like this can result in memory leak because Node hold the GLState and GLState hold GLProgram, while GLState will create in GLProgramStateCache and never be release automatically.

We must use removeUnusedGLProgramState by ourself.

What's more, lua do not bind GLProgramStateCache::removeUnusedGLProgramState().

[ricardoquesada]

yes, the fix is to expose removeUnusedGLProgramState to Lua.