new tube rendering by Jens Olav Nygaard
Bugfixes and cleanups in new well shaders.
Update well_tube_fs.glsl

nothing's changed
Update Representation.cpp

removed unnecessary call
Merge pull request #18 from sintefmath/new_tubes

new tube rendering by Jens Olav Nygaard
fixes isse #16
Merge branch 'master' into new_gui