SPSS date formatting and consistent order of repeats in exports

Merge pull request #1054 from onaio/csv-ordered-repeats

XLSForm order in repeats for Flat CSV exports

Export improvements and Django 1.11.1

• Improved export functionality (#1030)
• SPSS export fixes (#1024)
• Webhook posts data edits and use the requests library (#1039, #1033)
• upgrade to Django 1.11.1 (#1038 )
• Handle deleted XLSForm IOError exception (#911)
• update install instructions (#1034)

XForm version proper use

• Set XForm version in the submission XML and not the current active one #1018
• Fix version exports #1020
• Check XForm.require_auth when downloading a specific XForm #1022
• Filter out deleted submissions in attachments export #1027

Submission XForm version

• Set XForm version in the submission XML and not the current active one #1018
• Fix version exports #1020
• Check XForm.require_auth when downloading a specific XForm #1022

Single form formList

Merge pull request #1015 from onaio/enketo-only-formlist

single form formList for enketo usage

Fix project XForm list cache

Merge pull request #1009 from onaio/cache-forms

set xforms cache correctly for BaseProjectSerializer

Upgraded to Django 1.11

Merge pull request #1007 from onaio/cache

upgrade to django 1.11

Set project permission to a form asynchronously

Merge pull request #1006 from onaio/set-xform-permissions-async

Set xform permissions async.

Bug fixes and use of TextIt v2 API

• Create a user profile when none exists on /user endpoint, fixes #991
• Use TextIt/RapidPro v2 API, fixes #995
• Set cache correctly with xform submissions counts, fixes #975
• Raise AuthenticationFailed for Attribute errors, fixes #905
• Handle AsyncResult that are exceptions, fixes #997
• Set ZIP_DEFLATED and allowZip64=True in creating zip files, fixes #988
• Switch to using django storage for csv import processing, fixes #1002

Fix csv builder AttributeError

• Repeat columns with slashes were being replaced with underscores before being flattened. The fix was to perform the replacement after the columns were flattened. Closed issue #920