[#57] Add default_tags and default_extras handling
Update spatial-search.rst

Add a clue for locating the solr schema.xml file
Minor clarification for template extension

When creating a minimal custom theme users may start with a blank read.html file and include only the secondary_content block. This will fail, as the template needs to start with ckan_extends.
Update csw.py

Fix copy paste error
Merge branch 'boabjohn-patch-1'
Merge branch 'patch-2' of https://github.com/boabjohn/ckanext-spatial into boabjohn-patch-2
Merge branch 'boabjohn-patch-2'
Merge branch 'patch-1' of https://github.com/morty/ckanext-spatial into morty-patch-1
Merge branch 'morty-patch-1'
Merge branch '57_default_tags_extras' of https://github.com/geosolutions-it/ckanext-spatial into geosolutions-it-57_default_tags_extras
Merge branch 'geosolutions-it-57_default_tags_extras'
fix refs
Merge branch 'tomkralidis-doc-url-fix'