Fix various typos

Found via `codespell -q 3 -L aci,ake,aline,alle,alledges,alocation,als,ang,anid,apoints,ba,beginn,behaviour,bloaded,bottome,byteorder,calculater,cancelled,cancelling,cas,cascade,centimetre,childrens,childs,colour,colours,commen,connexion,currenty,dof,doubleclick,dum,eiter,elemente,ende,feld,finde,findf,freez,hist,iff,indicies,initialisation,initialise,initialised,initialises,initialisiert,inout,ist,kilometre,lod,mantatory,methode,metres,millimetre,modell,nd,noe,normale,normaly,nto,numer,oce,oder,ontop,orgin,orginx,orginy,ot,pard,parm,parms,pres,programm,que,rady,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,./build/doc/SourceDocu`

src/Mod/TechDraw/Gui/CommandExtensionDims.cpp

@@ -958,7 +958,7 @@ CmdTechDrawExtensionCascadeObliqueDimension::CmdTechDrawExtensionCascadeObliqueD
     sMenuText       = QT_TR_NOOP("Cascade Oblique Dimensions");
     sToolTipText    = QT_TR_NOOP("Cascade oblique dimensions\n\
     - select some parallel oblique measures\n\
-    - the first selected maesure defines the position\n\
+    - the first selected measure defines the position\n\
     - click this button");
     sWhatsThis      = "TechDraw_ExtensionCascadeObliqueDimension";
     sStatusTip      = sToolTipText;
@@ -1082,7 +1082,7 @@ void CmdTechDrawExtensionCascadeDimensionGroup::languageChange()
     arc3->setToolTip(QApplication::translate("TechDraw_Extension",
         "Cascade oblique dimensions\n\
     - select some parallel oblique measures\n\
-    - the first selected maesure defines the position\n\
+    - the first selected measure defines the position\n\
     - click this button"));
     arc3->setStatusTip(arc3->toolTip());
 }

src/Mod/TechDraw/Gui/MDIViewPage.cpp

@@ -520,7 +520,7 @@ void MDIViewPage::fixOrphans(bool force)
                     }
                 }
                 if (!found) {
-                    //none of the parent Pages for View coorespond to this Page
+                    //none of the parent Pages for View correspond to this Page
                     m_view->removeQView(qv);
                 }
             }