The behavior of the Draft_SelectGroup command was a bit cryptic. Layers were also regarded as groups. And the selection result was not the same if a nested object, instead of the group that object was in, was selected. The new version selects all objects in the `Group` property of the selected groups (or group-like objects). Nested groups are selected, but their contents is not.
For consistency the get_group_contents function should use is_group to identify groups. The code dedicated to Site objects and Drawing pages was removed.
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`
1. Draft_Snap_Parallel only worked beyond the endpoints of the edge.
2. It was very hard to select an edge for Draft_Snap_Parallel if no other snaps were active.
3. Only two snap objects were stored.
The findMidpoint function (used by Draft_Snap_Midpoint) only worked for straight and circular edges. With this revision the midpoint of all edges can be found.
The getTeighaConverter function did not work on Windows. We don't deal with the actual TeighaFileConverter anymore so there is no need to check for that file. Although the name of the function and the name of the parameter have been kept.