GLES2 translator: fix point rendering

if points are rendered the built in shader variable gl_PointSize should be active.
added a call to enable VERTEX_PROGRAM_POINT_SIZE to signal opengl to activate this variable
GL_POINT_SPRITE should also be enabled when rendering points

Change-Id: Iba7f62844ee2208ae22700b985aef0229d75fc46
2 files changed