changed sub-code handling

combined parentheses and colon sub-codes (never used with same codes)
removed none sub-code (use default sub-code enumerator instead)
added three unused sub-code enumerators for unused sub-code bits

added command table flag for operators that are really commands
- comma, semicolon, and assignments
- (needed for combining parentheses and colon sub-codes)
- check command flag in recreator operator function
- check command flag in program model stream insert operator function
- check command flag in test token stream insert operator function
removed unnecessary multiple table flag on two MID$ entries

changed sub-code arguments from integer to sub-code enumeration type
changed sub-code variables to unsigned 16-bit type where needed
changed integer constant token constructor to value convert initializer
- conversion needed to prevent narrowing error (was in constructor body)