Variable type functions refactored.

Such functions have been significantly improved, principally to support
efficient testing of multiple variables all-at-once but also to support early
functionality now requiring such functions.

"All in all,
 We're just another
 Function in the functional wall
 Of didactic prose
 Or unctuous rosewater
 (voluptuous in its
  ridgeless ray tracery, exasperatingly)
 Bridging untimely
 Brigadier generals, wastrels, and the
 Miskempt sellswords
 Of these wastelands
 Inward, and ignoble."