(1) removed CGAL finder since a better one is shipped with CGAL. (2) adapted PhySim finder to handle qwt as optional dependency. (3) added Geogram finder

Fix warning about glext redefiniton.

See merge request !150

Warning was:

/usr/include/x86_64-linux-gnu/qt5/QtGui/qopenglext.h:60: warning: "GL_GLEXT_VERSION" redefined
 #define GL_GLEXT_VERSION 20170325
 /usr/include/GL/glext.h:54: note: this is the location of the previous definition
 #define GL_GLEXT_VERSION 20180725

cf: https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/commit/5479af133ffe6077aab8a8be8f397f246aacb773

Matrix3x3T: implement setRow/setCol.

See merge request !149

ClippingNode: Operate in world coordinates

See merge request !148

This fixes clipping for instanced rendering and other situations with
non-identity model matrices.

choose glut primitve lighting based on draw mode

See merge request !147

add GlutPrimitiveNode-ConeSupport

See merge request !146

pick up tests in Type-* subdirs

See merge request !145

fake successful finder run for glew

See merge request !144

TriangleBSP: fix preprocessor guard

See merge request !143

Feature plugincommandlineoptions

See merge request !142

Merge branch 'master' of www.graphics.rwth-aachen.de:OpenFlipper-Free/OpenFlipper into feature_plugincommandlineoptions

docs: fix compilation of example plugins.

See merge request !140

I didn't check yet if this is enough to make them compile on current OF,
but it's a start.