Trajectory analysis tools added

modules/mol/alg/doc/molalg.rst

modules/mol/alg/pymod/export_trajectory_analysis.cc

modules/mol/alg/src/trajectory_analysis.cc

modules/mol/alg/src/trajectory_analysis.hh

modules/mol/base/pymod/CMakeLists.txt

modules/mol/base/pymod/wrap_mol.cc

modules/mol/base/src/coord_frame.cc

modules/mol/base/src/coord_frame.hh

modules/mol/base/src/coord_group.cc

modules/mol/base/src/coord_group.hh