OpenGL Updates - fix effects for both D3D & OGL

I had to edit this via the GitHub editor. I finish up my changes, and for some reason the pcsx2 repository won't let me read or write to it, since the last merge. I checked my other repositories, and they're working fine. ?.?
Tabbing >.>
Update GSSettingsDlg.cpp

Just add the OGL shader ini params to the file when the user enables post-processing In the options dialog.
Rearrange to right spot (I blame github editor ;p)
Small oversight fix for "sample_texLevel"
A few last bits of cleaning before merge.
Fix Cel Shader for OpenGL.
Merge pull request #344 from Asmodean-/master

[GSdx] OpenGL PP Updates