Spawn gevent using same python executable

Solves issues of spawning wrong version of python or popping out of virtualenv
[IMP]document: Remove document menu and submenu from knowledge, hr_applicnt_document: add kanban view in hr resume and letter, mail: change the kanban view of attachment
[IMP] take into account the context parameter 'defer_parent_store_computation' also on write operations
Merge pull request #746 from acsone/master-defer_parent_store_computation-on-write

[IMP] orm: defer_parent_store_computation in write

Take into account the context parameter 'defer_parent_store_computation' in write operation.
When executing actions with this key in the context, _parent_store_compute should be manually called afterwards. Use at your own risks...
Merge pull request #727 from odoo-dev/master-document-fix-issue-gan

[IMP] document: remove from knowledge + view type fixes
Merge pull request #528 from bwrsandman/patch-1

[FIX] Spawn gevent using same python executable