Restructure files, split large python files

Fix views

* Add binding on sales orders
* Ensure that we always have the Connector Manager group on the
  Connector tabs (most are done in the parent views of
  connector_ecommerce)
* Fixed inheritance of the delivery.carrier view

Collection.work_on is now a context manager

Add a base listener and use it in partner export

Rewrite tests using new API and vcr.py

* Use vcr.py to record the exchanges instead of a self-made recorder
* Use new base Components test case classes
* Separate export tests in 2 phases: trigger of the export which check
  that the jobs are delayed, and test the job itself in a second test

Update documentation

Various fixes

Add dependency on product_multi_category

I removed it earlier, but it is required when we import products

Fix Pylint warnings

Remove deprecated select for index creation

[FIX] pass http credentials to backedn component if required

[FIX] change user on backend otherwise import sale order will be done on the wrong one

[CHG]review product aggregation by backend to improve performance

Remove related_action from import_batch

Add Magento Enterprise Gift Cards payment line.

Unpacks the giftcard code from the PHP serialized information about the giftcards using regex.

Don't add a 0 amount Giftcard line.

Since the value will be a string like '0.0000', the prior tests were insufficient to prevent always adding a line.

Fix failing test

* Rename it because it was shadowing another test
* Compute in the location's context

Add Rewards and StoreCredit payment methods.

(Travis Bump)

[MIG] connector_magento to v11