Fixed bug in documentation for WholeMolecules

Action::registerKeywords and ActionPilot::registerKeywords were
not called in WholeMolecules::registerKeywords

(cherry picked from commit 53a5b885)

src/generic/WholeMolecules.cpp

@@ -108,6 +108,8 @@ public:
 PLUMED_REGISTER_ACTION(WholeMolecules,"WHOLEMOLECULES")
 
 void WholeMolecules::registerKeywords( Keywords& keys ){
+  Action::registerKeywords( keys );
+  ActionPilot::registerKeywords( keys );
   ActionAtomistic::registerKeywords( keys );
   keys.add("compulsory","STRIDE","1","the frequency with which molecules are reassembled.  Unless you are completely certain about what you are doing leave this set equal to 1!");
   keys.add("numbered","ENTITY","the atoms that make up a molecule that you wish to align. To specify multiple molecules use a list of ENTITY keywords: ENTITY1, ENTITY2,...");