[IMP] project: select project pricelist based on customer pricelist

Add an invisible field `pricelist_id` to project.project form view, so that when
`partner_id` is changed, `onchange_partner_id` method can also set the
pricelist properly (previously, the pricelist was not set because the
field was not in the view).
[IMP] website.snippet: snippets can be splitted into separate template and be called into the lits of the snippet
[IMP] website.snippet: add data-oe-call to call a template from the website and keep all content editable; used for demo page of snippets
[FIX] website fix image controller for xmlid
[FIX] website_links ZeroClipboard location

move ZeroClipboard to lib
remove useless map file
[IMP] convert.py xml <odoo> parsing and cleanups

- deprecate <url> tag
- deprecate multi levels name for <menuitem>
- <odoo> <openerp> <data> tags are now equivalent and may be nested, it means
  that the <data> tag is now optional and should only be used if the same xml
  file contains both update and noupdate records.

Only the base_menu.xml has been converted to the new format as an example.
Other files will be be progressively converted to avoid useless conflicts in
forward ports.
[ADD] website_slides: new module doing stuff. I swear.

Courtesy of a lot of people including Mantavya Gajjar(mga-odoo), Ravi Gadhia(rga-odoo),Vijay Patel(vip-odoo), Pariket Trivedi(ptr-odoo)

[REVIEW] Pre-merge review. This commit will have to
be squashed, but not before the end of the review process.

[FIX] broken uploader: for url upload provide image preview

[FIX] broken things after refatoring

[FIX] view count

[FIX] view_count and runbot error

[FIX] small issue related to slide like and most_viewed slides side bar

[FIX] grid view layout

[FIX] side panel layout

[FIX] download and fullscreen

[FIX] suggested slide layout

[FIX] notification mail send

[FIX] channel grid view layout

[FIX] embeded view

[IMP] slide embed pdf viewer