[MERGE] ir-ui-view split active and show_customize

Split the ternary field application in active and show_customize, all four
possible value are now needed for the customize theme popup.
[FIX] website info view remove optional tag
[ADD] port security reference doc
[ADD] openerp.http reference doc

* fix some docstrings so they can be autodoc'd
* intersphinx mapping (and links to) werkzeug and python
[ADD] web client tutorial/training

needs fixes, and corresponding web client reference
[FIX] http.py: session id is `sid` attribute
[IMP/REF] Enabling inheritance of product.pricelist.items via context and additional methods without the need to overwrite method _price_get_multi() completely by adding two hooks