Avoid unnecessary db query on index update

pks_seen is only needed if objects are removed from
index, so only compute it if necessary.
Improve pks_seen to not build an intermediary list.
Use HTML5 <input type=search> (closes #899)
Merge pull request #899 from acdha/html5-input-type=search

Search form <input type="search">
Use elasticsearch-py instead of pyelasticsearch.

elasticsearch-py is the official Python client for Elasticsearch.
Merge pull request #885 from HonzaKral/elasticsearch-py

Use elasticsearch-py instead of pyelasticsearch.
upgraded python3 in tox to 3.3

3.3 is a better target for haystack than 3.2, due to PEP414
Merge branch 'master' into avoid-pks-seen-on-update

Change smart_text into smart_bytes as in master

Conflicts:
	haystack/management/commands/update_index.py
Merge pull request #775 from stefanw/avoid-pks-seen-on-update

Avoid unnecessary, potentially huge db query on index update
Fix url for solr 3.5.0
Merge pull request #907 from gam-phon/patch-1

Documentation: updated download url for solr 3.5.0

Thanks @gam-phon for the pull request
Move test Solr instructions into a script

These will just rot horribly if they're not actually executed on a
regular basis…
tests: update requirements to match tox
Tests: update Solr schema to match current build_solr_schema

* Added fields used in spatial tests: location, username, comment
* Updated schema for recent Solr
* Ran `xmllint --c14n "$*" | xmllint --format --encode "utf-8" -`
Tests: update test_quotes_regression exception test

This was previously relying on the assumption that a query would not
match, which is Solr version dependent, rather than simply
confirming that no exception is raised
Tests: update test_more_like_this for Solr 4.6
Docs: fix ReST syntax error in searchqueryset_api.rst
Fix bounding box calculation for spatial queries (closes #718)

Thanks @jasisz for the fix
Whoosh: allow multiple order_by() fields

The Whoosh backend previously prevented the use of more than one
order_by field. It now allows multiple fields as long as every field
uses the same sort direction.

Thanks to @qris, @overflow for the patch

Closes #627
Closes #919
Allow users to pass in additional kwargs to Solr and Elasticsearch backends

Fixes #674, #862
Doc formatting fix