Just a minor bug in angle_btw_triangles
I have added the source tex files for object-in-fluidUG located in samples/object-in-fluid/object-in-fluidUG.

I have corrected the NAN in angle_btw_triangles. The problem was that I computed sqrt from a negative value.

Also, I unified the computation of the angle between triangles with tcl script. in scripts/object-in-fluid.tcl, in procedure angle_btw_triangles, there was still old way of computation of the angle. So I changed it accroding to the function in utils.h.

Ivan
Merge branch 'master' of github.com:espressomd/espresso
Clarified starting command
Removed incorrect citation for Langevin thermostat
Merge remote-tracking branch 'upstream/master' into p3m_gpu
Added test case for p3m_gpu, fixed an initialization bug, Espresso now checks for GPU capability~
Fixed data file for p3m_wall_gpu.tcl test case, moved check for GPU capability to cuda_common.cu
Merge remote-tracking branch 'georg/p3m_gpu' into p3m_gpu
Fixed errtxt bug causing ELC to fail with cpu code.  P3M still a bit slow and only cubic, although it does not throw an error for non-cubic boxes