[1407] WIP - Remove resourcegroups.

Contains a migration to remove the resourcegroups and have the resource
have a reference direct to it's package, this removes a lot of joins.

Drop constraint on resource_group_revision that travis complains about (but local install does not)
Minor tweaks, need completing
Put the test core back how it should be
Fixes #1596 by ensuring it only shows active members.

Currently removing a user from a group/org (marking membership as deleted)
then it still gets returned in dataset/new as a viable organisation/group to
choose when it isn't (as the user is not actually still a member).
Merge conflict
[1407] WIP - Remove resourcegroups.

Contains a migration to remove the resourcegroups and have the resource
have a reference direct to it's package, this removes a lot of joins.

Drop constraint on resource_group_revision that travis complains about (but local install does not)
Minor tweaks, need completing
Put the test core back how it should be
Merge branch '1407-remove-resourcegroups' of github.com:okfn/ckan into 1407-remove-resourcegroups

Conflicts:
	ckan/logic/action/get.py
	ckan/logic/schema.py
	ckan/model/resource.py
Test fixes for removing resource groups, stuck in test_dictization where the resource in expected package cannot know the package_id
More passing tests
Simplifies resource view nav into nav-tabs
Simplifies the embed modal code also added semantics
$ not jQuery
[#832] Remove FormAlchemy definitely

This includes, apart from the library requirement, the field_types module,
which has been unused for a very long time, and some unused converters
as well.
[#912] Display org title (if available) on dataset form field
[#1457] Split test
Ensure that field names are stripped #1970
[#1996] Fix featured group link.

URL was previously set as a jinja template variable, but was being
called inside a child block of the template, so the var was out of
scope and coming up empty. See:
http://jinja.pocoo.org/docs/dev/templates/#block-nesting-and-scope
unicode_or_json_validator should assume literals are unicode rather than json #1966