Fix typos, grammar, and some whitespace issues

Found via `codespell -q 2 -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/Mod/TechDraw/Gui/QGIPrimPath.h

@@ -91,8 +91,8 @@ protected:
     Qt::PenCapStyle m_capStyle;
 
     QBrush m_brush;
-    Qt::BrushStyle m_fill;                      //current fille style
-    Qt::BrushStyle m_fillStyle;                 //current fill style*/
+    Qt::BrushStyle m_fill;                      //current fill style
+    Qt::BrushStyle m_fillStyle;                 //current fill style
     QColor m_fillColor;                         //current fill color
 
     QColor m_colDefFill;                        //"no color" default normal fill color