Fix source comment 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,childs,colour,colours,commen,connexion,currenty,dof,doubleclick,dum,eiter,elemente,ende,feld,finde,findf,freez,hist,iff,indicies,initialisation,initialise,initialised,initialises,initialisiert,ist,kilometre,lod,mantatory,methode,metres,millimetre,modell,nd,noe,normale,normaly,nto,numer,oder,ontop,orgin,orginx,orginy,ot,pard,parms,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,./build/doc/SourceDocu`

src/Mod/Draft/draftguitools/gui_edit_base_object.py

@@ -64,7 +64,7 @@ class GuiTools:
     def get_edit_point_context_menu(self, edit_command, obj, node_idx):
         """ Get the context menu associated to edit points (user is over an editpoint)
 
-        Return a list of tuples containig menu labels and associated functions:
+        Return a list of tuples containing menu labels and associated functions:
             return [
                 ("action label", lambda: self.handle_action_label(edit_command, obj, node_idx)),
             ]
@@ -79,7 +79,7 @@ class GuiTools:
     def get_edit_obj_context_menu(self, edit_command, obj, position):
         """ Get the context menu associated to edited object (user is over the object)
 
-        Return a list of tuples containig menu labels and associated functions:
+        Return a list of tuples containing menu labels and associated functions:
             return [
                 ("action label", lambda: self.handle_action_label(edit_command, obj, position)),
             ]

src/Mod/Draft/draftguitools/gui_selectplane.py

@@ -137,7 +137,7 @@ class Draft_SelectPlane:
                 self.display(FreeCAD.DraftWorkingPlane.axis)
             return None
 
-        # Execute the actual task panel delayed to catch posible active Draft command
+        # Execute the actual task panel delayed to catch possible active Draft command
         todo.delay(FreeCADGui.Control.showDialog, self.taskd)
         _msg(translate(
                 "draft",