Adds proper group parsing

Makes the parser properly ignore aborted groups.
Makes group parsing controllable at runtime.

Adds the global variable 'morkDoNotParseGroups' that if set
true will cause the parser to treat any '@' surrounded strings
as meta strings to be ignored.

This will result in all groups being loaded even if aborted.

It will also result in faster operation because the entire
content of the group will not need to be 'ungetted' and the
'regetted'.
Adds command line option '-g' to block groups

Putting the '-g' command line option on will result in the
group header and footer strings being ignored as meta strings.

This will cause all groups to be loaded, even those that have
been aborted in their footers.

It will, however, result in faster runtime because the contents
of the group will not need to be "ungetc"ed and then read a second
time. It might also prevent failure if the support library or
memory available limits the number of characters that ungetc()
can buffer.