Fix various (doxy) typos and whitespace issues

Found via `codespell -q 3 -L aci,ake,aline,alle,alledges,alocation,als,ang,anid,ba,beginn,behaviour,bloaded,byteorder,calculater,cancelled,cancelling,cas,cascade,centimetre,childs,colour,colours,commen,currenty,dof,doubleclick,dum,eiter,elemente,feld,freez,hist,iff,indicies,initialisation,initialise,initialised,initialises,initialisiert,ist,kilometre,lod,mantatory,methode,metres,millimetre,modell,nd,noe,normale,normaly,nto,numer,oder,orgin,orginx,orginy,ot,pard,pres,programm,que,recurrance,rougly,seperator,serie,sinc,strack,substraction,te,thist,thru,tread,uint,unter,vertexes,wallthickness,whitespaces -S ./.git,*.po,*.ts,./ChangeLog.txt,./src/3rdParty,./src/Mod/Assembly/App/opendcm,./src/CXX,./src/zipios++,./src/Base/swig*,./src/Mod/Robot/App/kdl_cp,./src/Mod/Import/App/SCL,./src/WindowsInstaller,./src/Doc/FreeCAD.uml`

src/App/DocumentObject.cpp

@@ -361,7 +361,7 @@ std::vector<App::DocumentObject*> DocumentObject::getInListRecursive(void) const
 
 #else
 // The original algorithm is highly inefficient in some special case.
-// Considering an object is linked by every other objects. After exculding this
+// Considering an object is linked by every other objects. After excluding this
 // object, there is another object linked by every other of the remaining
 // objects, and so on.  The vector 'result' above will be of magnitude n^2.
 // Even if we replace the vector with a set, we still need to visit that amount
@@ -1197,4 +1197,3 @@ void DocumentObject::onPropertyStatusChanged(const Property &prop, unsigned long
     if(!Document::isAnyRestoring() && getNameInDocument() && getDocument())
         getDocument()->signalChangePropertyEditor(*getDocument(),prop);
 }
-