first implementation of the affinity
The rotation of oif's was corrected
proper normalization
New force added, called stretchlin, it is almost the same as streching force, however, in stretching force the string defined by this force is nonlinear, with neo-hookean dependence of stiffness constant. Stretchlin is purely linear.
One file fortgotton in previous commit
Merge branch 'espressomd_master' into espresso-object-in-fluid

Conflicts:
	src/Makefile.am
	src/energy.h
	src/forces.h
	src/tcl/interaction_data_tcl.c
Removed remaining fsi files
scripts/object-in-fluid.tcl - Generation of bending forces changed. Now, bending forces are generated only for those edges that have two triangles next to them. This means, that also open objects can be simulated.
Kai Szuttor's fix.
Small fix so that the test case doesn't fail.
Merge branch 'master' into cpp
Added print exclusions
copy_particles now also copies exclusions
Resorted NEWS
Cleaned up NEWS for 3.3.
Merge Ivan's changes
Merge branch 'master' of github.com:espressomd/espresso
Merge branch 'master' into cpp

Conflicts:
	src/Makefile.am
	src/energy.hpp
	src/forces.hpp
	src/tcl/interaction_data_tcl.cpp
Define isnan() for C++98 compatibility
Merge pull request #109 from mkuron/osx-cpp

Define isnan() for C++98 compatibility