Ark
refs #6982 - a replace for all config usages - always use config.get or config.set - this a pure replacement, no logic has changed [ci skip]
refs #6982 - do not add the subdir property as static config value - create functions to read subdir and protected slugs on runtime
closes #5914, #6589 - moves all private-blogging related code & tests into /server/apps/private-blogging/ - rework Grunt to run private-blogging tests - modify server apps code to have a place for internal apps