This change tries to merge the new Z-Spec definition for print_table
and to make "Sherlock" work with it. According to the new spec,
print_table shouldn't be used in the lower window. Sherlock however
appears to require this to display error messages correctly. libfizmo
now allows the print_table opcode to work in the lower window, but
simply shows the opcode's text without any cursor movement.

Implemented “flush-output-on-newline” configuration option. This will
ensure that any output is flushed to history and interface before a
newline. This allows interfaces to store paragraph-relevant attribtues
in the history with minor fuzz.

Added new metadata-type “paragraph attribute” for the purpose
described above.

Minor changes in processing when converting font 3 to unicode.

Implemented counting of wraparounds to implement new function
"validate_outputhistory", replaces "has_wrapped".

The "validate_outputhistory" function return true if the history object
in question is still valid, false if not.

Added "rewound_paragraph_was_newline_terminated" flag so it's possible
to tell whether the last paragraph in the output has been newline-
terminated or not.

Did some code-cleanup.