Replace F94 with F12

Removed ed11 markup

Significant revisions to
A.1 (Introduction),
A.7 (Block word set),
A.11 (File-Access word set),
A.12 (Floating-Point word set),
A.13 (Locals word set),
A.16 (Search-Order word set)

Minor revisiosn to
A.2 (Terms and notations),
A.3 (Usage Requirements)

Moved implementation of CATCH THROW QUIT and ABORT from A.9 (Exception word set) to Implementation.