fixing webstart index page that allows to set custom intro page for OMERO.web
removing unnecessary import
Merge remote-tracking branch 'origin/develop' into webstart_index_template
adding default template
adding never_cache decorator to always create a 302
and not cache webstart page
making TEMPLATE_DIRS configurable in settings
updating webstart url pattern
making INDEX_TEMPLATE configurable to define intro page
Merge pull request #2210 from aleksandra-tarkowska/webstart_index_template

Webstart index template