Fix detection of MIME type in message_parse()

Be careful, content-type may contain tricky content like in the
following example so test the MIME type with startswith()

Content-Type: multipart/related;
  boundary="_004_3f1e4da175f349248b8d43cdeb9866f1AMSPR06MB343eurprd06pro_";
  type="text/html"
[FIX] base: security, group settings is authorized to alter ir.config_parameter
[FIX] base: security, do not override basic ir_config_paramter ACL
Merge pull request #286 from jbq/bugfix

[FIX] mail: detection of MIME type

When parsing the mail headers, the content-type may has a 'type' attribute for Multipart/Related  objects (rfc2387).
Previous check would match on attached files of type text instead of real `content-type: text/`.
[FIX] calendar: avoid double popup, opw 606297

Some browsers (e.g. chrome) trigger onEmptyClick as well as
onBeforeLightbox during drag&drop which calls two slow_create
calls (and two popups). Workaround to kill the second one.
[FIX] delivery: allow to add delivery method in quotation if quotation in quotation sent stage

opw-607920
[FIX] sale: keep customer reference in grouped invoice (opw 606523)
[FIX] stock: use correct vals in grouped invoice (opw 606535)

When creating a grouped invoice, the invoice_vals value is used to create the invoice line.
The value was not reset for grouped invoice and we reused the values of previous line.
[FIX] kanban: avoid wrong placement of button on ie9

On ie9, the 'read more' button in kanban view was placed in the middle of the window instead of the bottom
[FIX] point_of_sale: correct call to default value

The default value should be called with a lambda otherwise the payment_date is set to the date the server was started (opw 606715)
uninstall: avoid errors during uninstall

When uninstalling a module, remove the ir.model.constraint after removing the non-model records and before fields and model definition.
Without this fix, some constraint would be removed too early allowing to have broken relations and data left from removed module.
[FIX] web: many2many field handle "no_create" option
Merge branch '7.0' of https://github.com/odoo/odoo into 7.0