Add tests to repository

tests/bond/analysis/get-data.tcl

tests/bond/analysis/plotTools.py

tests/bond/bondfile.txt

tests/bond/coord.txt

tests/bond/diffusion.POT.dx

tests/bond/dummy-pot.dat

tests/bond/dummy-pot.py

tests/bond/extend114_pot-pot.dat

tests/bond/null-pot.dat

tests/bond/null.dx

tests/bond/null2.dx

tests/bond/run.sh

tests/langevin/Langevin.bd

tests/langevin/analysis/Makefile

tests/langevin/analysis/get-data.tcl

tests/langevin/analysis/plot.plt.py

tests/langevin/analysis/plotTools.py

tests/langevin/pmf.dx

tests/langevin/run.sh

tests/langevin/vdw.dat