Fixed typo in example

It should be `css_class` in the template tag example instead of just `class`. (It is mentioned correctly in the syntax line earlier).
RelatedSearchQuerySet: move class globals to instance properties

This caused obvious failures in the test suite and presumably
elsewhere when multiple RelatedSearchQuerySet instances were in use
Test refactor - merge all the tests into one test suite (closes #951)

Major refactor by @honzakral which stabilized the test suite, makes it easier to run and add new tests and
somewhat faster, too.

* Merged all the tests
* Mark tests as skipped when a backend is not available (e.g. no ElasticSearch or Solr connection)
* Massively simplified test runner (``python setup.py test``)

Minor updates:
* Travis:
    - Test Python 3.4
    - Use Solr 4.6.1
* Simplified legacy test code which can now be replaced by the test utilities in newer versions of Django
* Update ElasticSearch client & tests for ES 1.0+
* Add option for SearchModelAdmin to specify the haystack connection to use
* Fixed a bug with RelatedSearchQuerySet caching using multiple instances (429d234)
Release v2.2.0
Merge pull request #1025 from reinout/patch-1

Fixed typo in templatetag docs example (thanks to @reinout)
Update Xapian install
Fixed the installing search engine doc URL
Link to 'signal processors'
Merge pull request #1047 from g3rd/patch-1

Update the installing search engine documentation URL (thanks @g3rd)
Merge pull request #1050 from jogwen/patch-2

Documentation: add a link to signal processors in search index
Docs: fix signal processors link in searchindex_api

Correct a typo in b676b17dbc4b29275a019417e7f19f531740f05e
Merge pull request #1044 from areski/patch-1

Update Xapian install instructions (thanks @areski)
Add PyPy targets to Tox & Travis

Closes #1049
Update example for Faceting to reference page.object_list

Instead of `results` - ref #1052
Merge pull request #1053 from gandalfar/patch-1

Docs: update Faceting example with correct template context (thanks @gandalfar)
Fallback to pwd if realpath is not available
Merge pull request #1055 from andreif/feature/realpath-fallback-osx

Tests: Solr test server script now handles OS X without realpath / coreutils (thanks @andreif)
Travis, Tox: add Django 1.7 targets
Update Travis & Tox config

* Tox: wait for Solr to start before running tests
* Travis: allow solr & pip downloads to be cached
* Travis now uses start-solr-test-server.sh instead of travis-solr
* Test Solr configuration uses port 9001 universally as per the
  documentation
* Change start-solr-test-server.sh to change into its containing
  directory, which also allows us to remove the realpath dependency
* Test Solr invocation matches pysolr
    * Use get-solr-download-url script to pick a faster mirror
    * Upgrade to Solr 4.7.2
Tests: don't suppress Solr stderr logging

This will make easier to tell why Solr sometimes goes away on Travis