(captive portal) add option "drop expired vouchers", closes https://github.com/opnsense/core/issues/977

system_staticroutes_configure, remove dead code, add rc.newroutedns dependencies and make the optional alias use in static routes explicit with a typeahead

Lookie, privilege separation.  ;)

(filter, scrub) use firewall_scrub.php for traffic normalization. closes https://github.com/opnsense/core/issues/973

This reverts commit 88580477.

(filter, plugins, pppoe) work in progress, pppoe server contains more instances. wrap items in 'items' property, to maintain old code. eventually we may need to define the data structure better.

ditch disablescrub option,  fragment reassemble is enabled by default.

(firewall, normalization) add acl + menu for https://github.com/opnsense/core/issues/405 and move Schedules to same menu level

(legacy style code) work on https://github.com/opnsense/core/issues/405 packet normalisation, needed for further restructure and cleanup of filter code.

Spotted by: @fabianfrz

Also remove the captive portal RRD graph removal.  We really need
to improve the GUI in order to solve the issue of stale RRD files
gracefully.

PR: https://forum.opnsense.org/index.php?topic=3082.0