provide a config upgrade path to version 13 which nulls/frees out
theme config (save memory - but more housekeeping), and that also
copeis ofer all files in ~/.e/e/themes to ~/.elementary/themes so you
don't lose themes you personally have and deletes the old e theme dir
if this succeeds.
also remove all #includes of Elementary.h and Emotion.h from single c
files as they are requirements now and in e.h
also remove theme path vars and code as theme path is no longer used.