include @@daily-issue view + tests

Create DailyIssue BrowserView that creates and sends a enlissue for
the current day, using default template and search criteria.
Improve responses and tests for daily issues
Change permission to send daily issue to ManagePortal
Improve (again) responses and tests for daily issues
Differ GET from POST in @@daily-issue

GET is safe while POST can do real stuff.

HTTP Responses:

===================  ============  =====  ============
Method/Precondition  Not yet sent  Empty  Already Sent
===================  ============  =====  ============
GET                     100         204       200
POST                    200[*]_     204       409
===================  ============  =====  ============

.. [*] send issue first.
Include documentation for @@daily-issue
fix typo in README
Merge branch 'master' of git://github.com/trt13paraiba/Products.EasyNewsletter into trt13paraiba-master