[IMP] payment modules: added provider selection field that is different
from the name. This allows to distinguish name and provider. Provider is a more
technical field, used to call some specific methods (<provider>_method_name). The
name field is used for display on the website.

Code and views udpated accordingly.
[IMP] Tracks: alphabetic order
[MERGE] Sync with trunk
[ADD] website_sale: added inherit of the transaction
form view to display the sale_order_id field.
[IMP] payment: added name on transaction views
[IMP] payment_transfer: Transfer -> Wire Transfer + updated test
[FIX] website_sale: fixed tour
[FIX] website_sale: fixed stupid test usign a title
[IMP] event: performance improvement for event with large amount of registration.
[FIX] website_sale: fixed post_msg, display only when having it (may have False, None, ..)
[MERGE] [IMP] event: store number of seat used to avoid unnecessary computations (performance improvement)
[MERGE] [IMP] payment modules: added provider selection field that is different from the name. This allows to distinguish name and provider. Provider is a more technical field, used to call some specific methods (<provider>_method_name). The name field is used for display on the website.

Added name on payment.transaction views.

Added sale_order_id field on transaction form view; the field is already present and used but was not displayed.

Transfer is now called Wire Transfer.

Code and views udpated accordingly.