add layer-loading-button on first layer load
Merge pull request #1505 from aodn/issue_1452

Add layer-loading-button on first layer load
portal with no db, no filters
refactor layer controller for get filters requests
script to fetch and convert filters to xml

parsing of xml filters from local directory
simplify HostVerifier, also more secure

 * does not allow host because it's in the 'Host' HTTP header
 * faster search via hash map
 * reduce allow hosts to actual hosts
Removed another unused function
Remove splash pages (use landing page in favour)
Removed images and stylesheets not currently in use
Removed references to scanners, and Portal admin pages
Remove Mail and Quartz plugins
Remove more AODAAC code
Remove JS for Menu editing
Remove saved-search controller