Created Python API for ring polymer contraction

wrappers/python/src/swig_doxygen/OpenMM.i

@@ -31,6 +31,7 @@ namespace std {
   %template(vectorstring) vector<string>;
   %template(mapstringstring) map<string,string>;
   %template(mapstringdouble) map<string,double>;
+  %template(mapii) map<int,int>;
 };
 
 %include "windows.i"

wrappers/python/src/swig_doxygen/swigInputConfig.py

@@ -446,5 +446,6 @@ UNITS = {
 ("DrudeLangevinIntegrator", "getDrudeTemperature") : ("unit.kelvin", ()),
 ("DrudeLangevinIntegrator", "getDrudeFriction") : ("1/unit.picosecond", ()),
 ("DrudeSCFIntegrator", "getMinimizationErrorTolerance") : ("unit.kilojoules_per_mole/unit.nanometer", ()),
+("RPMDIntegrator", "getContractions") : (None, ()),
 }
 

wrappers/python/src/swig_doxygen/swig_lib/python/pythoncode.i

@@ -282,16 +282,9 @@ def stripUnits(args):
             # JDC: End workaround.
             #arg=arg.value_in_unit_system(unit.md_unit_system)
         elif isinstance(arg, dict):
-            newArg = {}
-            for key in arg:
-                newKey = key
-                newValue = arg[key]
-                if not _is_string(newKey):
-                    newKey = stripUnits(newKey)
-                if not _is_string(newValue):
-                    newValue = stripUnits(newValue)
-                newArg[newKey] = newValue
-            arg = newArg
+            newKeys = stripUnits(arg.keys())
+            newValues = stripUnits(arg.values())
+            arg = dict(zip(newKeys, newValues))
         elif not _is_string(arg):
             try:
                 iter(arg)