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/PropertyLinks.cpp

@@ -2428,14 +2428,14 @@ bool PropertyLinkSubList::adjustLink(const std::set<App::DocumentObject*> &inLis
 // DocInfo
 //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 
-// Key on aboslute path. 
+// Key on absolute path.
 // Because of possible symbolic links, multiple entry may refer to the same
 // file. We use QFileInfo::canonicalPath to resolve that.
 typedef std::map<QString,DocInfoPtr> DocInfoMap;
 DocInfoMap _DocInfoMap;
 
 class App::DocInfo : 
-    public std::enable_shared_from_this<App::DocInfo> 
+    public std::enable_shared_from_this<App::DocInfo>
 {
 public:
     typedef boost::signals2::scoped_connection Connection;
@@ -3099,7 +3099,7 @@ void PropertyXLink::Save (Base::Writer &writer) const {
         std::string _path;
         if(exporting) {
             // Here means we are exporting the owner but not exporting the
-            // linked object.  Try to use aboslute file path for easy transition
+            // linked object.  Try to use absolute file path for easy transition
             // into document at different directory
             if(docInfo) 
                 _path = docInfo->filePath();