Introduced group_id on owner_check().

May be used to allow group to alter objects.
Added cql modifier 'keeporder'.

SOLR normally orders by relevance. This modifier will try to maintain
the order as given with the field. This will work only in combination
with any (..). For example:

cql = asset_id any/keeporder (^lskdflsdkflskjd^ ^slkdfsdflsdfj^)
Included tool_image in a default installation.
Merge branch 'arjenk-feature/group-on-owner-check'
Merge pull request #147 from arjenk/feature/cql_keeporder

Added cql modifier 'keeporder'.
Merge pull request #148 from arjenk/feature/include_tool_image

Included tool_image in a default installation.
Version 3.6.0-dev build 2131.