set INSTALL_TO_SITEPACKAGES to ON by default

and add some modules to the freecad-namespace (freecad.part, freecad.partdesign, freecad.sketcher)

src/Ext/freecad/CMakeLists.txt

@@ -38,6 +38,9 @@ endif()
 INSTALL(
     FILES
         ${NAMESPACE_INIT}
+        part.py
+        partdesign.py
+        sketcher.py
         project_utility.py
         UiTools.py
         utils.py

src/Ext/freecad/part.py

@@ -0,0 +1 @@
+from Part import *

src/Ext/freecad/partdesign.py

@@ -0,0 +1 @@
+from PartDesign import *

src/Ext/freecad/sketcher.py

@@ -0,0 +1 @@
+from Sketcher import *