(def-construct flag-system parent (flags (make-hash-table)))
Function DEF-FLAG-SYSTEM flag systems may be children of other flag systems
Function CONCAT-FLAGS creates an integer using logior using a list of flags: e.
Macro FLAGS creates code using a flag-system and a list of args.
Macro DEF-FLAG* same as def-flag, but creates a constant
Function FLAG-LIST returns a list of flags, which byte pattern is found in value