e_foreign_shell: No longer use embedded client concept

e_foreign_shell: No longer use embedded client concept

There were some tricky side effects because of the concept of embedded
client which used smart object mechanism for re-stack operation. So,
this patch removes using the concept, instead it gives the
e_foreign_shell responsibility for re-stacking on its own.

This also reverts following patchs which are no longer used:

  commit 8b545ca9e79ef2c06fc383cf9cbc788d4561e1e7.
  Revert "e_comp_object: Set an embedded E_Client as comp_object ..."

  commit fd9f1eb3cc89980295d923894ea5e016a1a360c1.
  Revert "e_client: Introduce a way of embdding a client to ..."

Change-Id: I912e038da129665b5ba6a62fe7c94aa8dce89176