Fix crash running paster command with multilingual plugin

The multilingual plugin will crash if it's enabled when certain paster
commands are run. This fixes the crash.
[#1768] Fix for the home page - featured group/organization did not show its datasets.
Merge branch 'master' into 1768-organization-list
[#1768] Fix for the home page - regression test added.
[#1768] Fix for the home page - refix.
[#1968] Fix IGroupForm docstrings
Update docs for package and source install

Both source install and package install allows solr and postgres to be run on
separate servers.
Fix formatting
Add a note for configuring postgresql
Update Apache and Nginx config to be more modern
[#1984] exclude trailing ,.; in external link
[#1987] group_list returns groups of passed type.

group_list get action will return group types specified by passing
the optional parameter type=<group type>. The default is 'group'.
[#1987] PEP8ing before changes
[#1987] IGroupForm plugins can define controller.

If you're using a custom controller with an IGroupForm plugin you can
define it in the plugin with 'group_controller()'. This will be used
when registering the plugin mappings. Defaults to 'group' if not defined
in the plugin.
[#655] Add extra metadata fields by default
Merge pull request #1987 from brew/1987-custom-group-changes

Changes to allow better use of custom group types in IGroupForm extensions
[#1418] Better error messages for NAVL junk.
[#1984] Add test and improve readability.
Merge pull request #1990 from ckan/1985-autolink-punctuation

1985 autolink punctuation
[#1495] add res_type to solr schema