format/write (version 2)

format/write (version 2)
Message-ID: <DF27CDCBD2581D4B88431901094E4B4D02B0C4D3@attmsx1>

Fixes and additions to formats:

Improvement: NULL chars in picture line
Bugfix: C<@*> shown in output if not alone on a line
New feature: C<^*> for variable-width, one-line-at-a-time text
Improvement: Diagnostic on C<@#> and C<~~>
Bugfix: Segmentation fault on big numbers
Improvement (maybe): Truncation of numbers produces misleading output
Bugfix: "}" terminates format
Bugfix: Error when copying non-UTF to UTF (EBCDIC only)

p4raw-id: //depot/perl@22161