Template:Set combined required tech level

Given multiple tech level variables this finds the lowest tech level. If one is found, then:
 * 1) This sets Property:requires tech level
 * 2) If this page is not a Tool, Weapon, or Workspace, this also sets Property:Tech level sort order

Parameters
none

Checks existing variables
These can be an empty string, or a plain tech level name (no link markup).
 *  
 *  
 *  

Affected variables, properties, categories

 * Property:Requires tech level
 * Property:Tech level sort order (sets only if the page is not a Tool, Weapon, or Workspace)

Text output
none