ofShader: vertex attribute arrays need to be disabled on end()

I have recently experienced that using vertex attribute arrays from setAttribute3fv results in strange behavior on the Nvidia driver, but not on Intel. When the vertex attribute pointer was set - it caused strange yellowish drawing of all other content following the call.

After a lot of digging I found that the vertex attribute pointer need to be disabled after using the shader - otherwise it will affect subsequent drawing. Basically the glEnableVertexAttribArray need to be complemented with a call to glDisableVertexAttribArray.

Solutions:

1. As a minimum we could add a function called ofShader::disableAttributePointer.

2. Or, more advanced, setAttribute3fv should update a map with attributePointers that should be disabled on end();

Start by tracing ofShader::setAttribute3fv and ofShader::end(), focusing on where glEnableVertexAttribArray is called. Verify how enabled vertex attribute arrays affect subsequent drawing, then determine whether the affected attributes can be disabled during end() or through a separate disableAttributePointer entry point. Done means later drawing is no longer affected after using the shader.