TechLevel support
added a TechLevel system that is built around traits
added IprerequisiteProvider
changed LintBuildablePrerequisites to use an interface to check
changed ProvidesCustomPrerequisiteInfo to use the new interface
TechLevel UI added
Added basic TechLevels
Changed the checks for the ~ ! annotations
so you have to start the prereq with them and have ~ in front of !
changed default tech level and a copyright typo
also removed prereqs from tooltip that start with a ~