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/Mod/Fem/femsolver/run.py

@@ -74,7 +74,7 @@ def run_fem_solver(solver, working_dir=None):
         A document object which must be a framework compliant solver. This means
         that it should be derived from the document object provided by
         :mod:`femsolver.solverbase` and implement all required methods
-        correctely. Of particular importance is :meth:`getMachine
+        correctly. Of particular importance is :meth:`getMachine
         <femsolver.solverbase.Proxy.getMachine>` as it is used by this method
         the get the :class:`Machine` used to execute the solver.
 
@@ -154,7 +154,7 @@ def getMachine(solver, path=None):
         A document object which must be a framework compliant solver. This means
         that it should be derived from the document object provided by
         :mod:`femsolver.solverbase` and implement all required methods
-        correctely. Of particular importance is :meth:`getMachine
+        correctly. Of particular importance is :meth:`getMachine
         <femsolver.solverbase.Proxy.getMachine>` as it is used by this method
         to create a new :class:`Machine` on cache miss.