HUE-1811 [search] Sample collections

Create 3 examples of collections with several facets and features:
- twitter
- yelp
- log search

The index page of the collections works even without a valid solr for demo purpose.
The collections are moved from the search dropdown to the main menu bar.
Some sample data is available for filling a reald index. Some basic indexing scripts
are in progress in order to offer a good quick start experience.

We are using hardoced ids in the fixtures to keep it simple.

Todo:
- click on install examples installs the example
- add more data and finish the indexing scripts
- collection level permissions
- alert message when using a demo collection without a valid solr
HUE-1811 [search] Alert message when using a demo collection without a valid Solr
HUE-1811 [search] Install examples button in quick start wizard

Also display a landing page when no collections are setup
HUE-1811 [search] Add script for creating the Solr collections

Renamed the example collection to *_demo
[search] Adding sample icons
[search] Integrating icons for demo collections
[impala] Faster check status until 2s of execution
[core] Make about page available to anonymous user

That way a non logged in user can visite the About Hue page on the
login page.
[beeswax] Better multi query separation support

Now understand the "escaped by '\\'".
[core] Fix tests for RemoteDjangoUserBackend
HUE-1829 [beeswax] Add back MapReduce job list

Added overlay to logs with job links
HUE-1994 [impala] Autocomplete UDF arguments with table columns

Added autocomplete to functions
Fixed LIMIT autocomplete
Fixed recent queries column widths
HUE-1993 [hbase] Add examples for HBase App

Based on the tutorial:
http://gethue.tumblr.com/post/58181985680/hadoop-tutorial-how-to-create-example-tables-in-hbase
HUE-1996 [core] Prevent ajax caching on IE

Added ajaxSetup and removed all Math.random()
HUE-1930 [core] Alert users with older browsers to upgrade instead of showing a blank page

Added unsupported browser page
HUE-1930 [core] Alert users with older browsers to upgrade instead of showing a blank page

Removed weird characters from unsupported.mako
Added Firefox < 7 detection
HUE-1860 [core] sync ldap group memberships upon login

Add logic to the LdapBackend.
Add tests for LdapBackend.
[core] switch to checking for is_first_login_ever existance

This is more stable and enables other backends to use it.
It also fixes the tests.
[core] First pass of l10n for 3.5
[jobbrowser] Job counter error with Yarn

It turns out the proxy fetches data from the JobHistory Server,
which returns HTML even when requesting JSON. In this case,
we should return None.