Draft: add description of draftfunctions package

These modules provide supporting functions for dealing
with the scripted objects and Gui Commands defined
within the workbench.

If the functions do very basic tasks or are too generic,
they are more appropriate inside the `draftutils` package.

These function are imported in the main `Draft.py` module
so they form part of the public programming interface (API)
of the workbench.

Remove trailing spaces in CMakeLists.txt.

src/Mod/Draft/CMakeLists.txt

@@ -67,13 +67,14 @@ SET(Draft_functions
     draftfunctions/fuse.py
     draftfunctions/heal.py
     draftfunctions/join.py
-    draftfunctions/mirror.py    
-    draftfunctions/move.py    
-    draftfunctions/offset.py    
-    draftfunctions/rotate.py    
-    draftfunctions/scale.py    
-    draftfunctions/split.py    
-    draftfunctions/upgrade.py    
+    draftfunctions/mirror.py
+    draftfunctions/move.py
+    draftfunctions/offset.py
+    draftfunctions/rotate.py
+    draftfunctions/scale.py
+    draftfunctions/split.py
+    draftfunctions/upgrade.py
+    draftfunctions/README.md
 )
 
 SET(Draft_make_functions

src/Mod/Draft/draftfunctions/README.md

@@ -0,0 +1,16 @@
+2020 May
+
+These modules provide supporting functions for dealing
+with the custom "scripted objects" defined within the workbench.
+
+The functions are meant to be used in the creation step of the objects,
+by the "make functions" in `draftmake/`, but also by the graphical
+"Gui Commands" modules in `draftguitools/` and `drafttaskpanels/`.
+
+These functions should deal with the internal shapes of the objects,
+or other special properties. They should not be very generic;
+if they are very generic then they are more appropriate to be included
+in the modules in `draftutils/`.
+
+For more information see the thread:
+[[Discussion] Splitting Draft tools into their own modules](https://forum.freecadweb.org/viewtopic.php?f=23&t=38593&start=10#p341298)

src/Mod/Draft/draftfunctions/__init__.py

@@ -1,3 +1,41 @@
-"""Generic functions of the Draft Workbench.
+# ***************************************************************************
+# *   (c) 2020 Carlo Pavan <carlopav@gmail.com>                             *
+# *   (c) 2020 Eliud Cabrera Castillo <e.cabrera-castillo@tum.de>           *
+# *                                                                         *
+# *   This file is part of the FreeCAD CAx development system.              *
+# *                                                                         *
+# *   This program is free software; you can redistribute it and/or modify  *
+# *   it under the terms of the GNU Lesser General Public License (LGPL)    *
+# *   as published by the Free Software Foundation; either version 2 of     *
+# *   the License, or (at your option) any later version.                   *
+# *   for detail see the LICENCE text file.                                 *
+# *                                                                         *
+# *   FreeCAD is distributed in the hope that it will be useful,            *
+# *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
+# *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
+# *   GNU Library General Public License for more details.                  *
+# *                                                                         *
+# *   You should have received a copy of the GNU Library General Public     *
+# *   License along with FreeCAD; if not, write to the Free Software        *
+# *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  *
+# *   USA                                                                   *
+# *                                                                         *
+# ***************************************************************************
+"""Modules that contain functions for use with scripted objects and commands.
 
+These functions provide support for dealing with the custom objects
+defined within the workbench.
+The functions are meant to be used in the creation step of the objects,
+by the functions in the `draftmake` package, but also by the graphical
+GuiCommands in the `draftguitools` and `drafttaskpanels` packages.
+
+These functions should deal with the internal shapes of the objects,
+and their special properties. They should not be very generic;
+if they are very generic then they are more appropriate to be included
+in the `draftutils` package.
+
+These functions, together with those defined in the `draftmake` package,
+represent the public application programming interface (API)
+of the Draft Workbench, and should be made available in the `Draft`
+namespace by importing them in the `Draft` module.
 """