- Changes most `/* comments */` to `// comments`
- Changes `/**` block comments consistently to `/*`
- Adds consistent license comments to all files
Also renames `T_POP_SET` to `T_Z80_SET`
Simplify the mess that was option setting (2 redundant variables !?)
Move options to a separate file
Have "modules" own their options, and OPT only access them (less redundancy)
Simplify code, respect naming conventions better