avoid to delete __init__.py so that make after make clean does not fail
added rdf as core observable so that it can be used for averaging
Merge branch 'master' of https://github.com/espressomd/espresso

Conflicts:
	src/python/espressomd/Makefile.am
Fixed compilation with LB only.
Merge branch 'master' of https://github.com/espressomd/espresso
CPU+MPI of IBM virtual particles. Tested with test1 and test2 without thermal noise.
Added wall repulsion.
Fixed a bug in UpdateIBMParticles, ghost forces need to be reset for real particles always
Added CUDA
CUDA (this time including files)
Merge branch 'master' of https://github.com/espressomd/espresso
Added ibm_triel interaction
Added stuff volCons, wallRep and triel into interaction_data.cpp which had previously been forgotten
Added volume conservation
Fixed a bug in checkpoints for volcons and removed a few file headers
Added bending
Added bending (with files)
Merge branch 'master' of https://github.com/espressomd/espresso
Return TCL_OK in various tcl functions
Merge the immersed boundary code