add a message when solidify is used with only-edges, this isn't properly supported.

also minor edits to py-api-ref
-- This line, and those below, will be ignored--

M    doc/python_api/sphinx_doc_gen.py
M    doc/python_api/rst/include__bmesh.rst
M    source/blender/modifiers/intern/MOD_solidify.c

doc/python_api/sphinx_doc_gen.py

@@ -1538,8 +1538,8 @@ def write_rst_contents(basepath):
         "mathutils", "mathutils.geometry", "mathutils.noise",
         # misc
         "bgl", "blf", "gpu", "aud", "bpy_extras",
-        # bmesh
-        "bmesh", "bmesh.types", "bmesh.utils", "bmesh.ops",
+        # bmesh, submodules are in own page
+        "bmesh",
         )
 
     for mod in standalone_modules: