set correct content type on xml requests

introduced functions for expecting a specific content type (implemented
only for json and xml now)
move Ajax.js to prototypes dir

Ajax.js moved to prototypes directory so it will be updated every once
in a while, rather than be cached for almost ever
Merge pull request #1518 from aodn/content_type_xml

set correct content type on xml requests
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
remove redundant code for setting openlayers bbox

setting bbox only from metadata record
remove more unneeded js files

 * MenuItemToNodeBuilder
 * MenuTreeLoader
 * ServerNodeLayerDescriptorStore
fix get feature info for non-ncwms layers