special characters in package names

[George J. Carrette <GJC @ MIT-ML>]

Something like |;;|: is easy enough to parse as a package prefix.
I would implement this in the NIL reader by putting a PEAK-CHAR
case on the char-macro for |. Of course, a user could already have
typed this in as \;\;: so there is no need to have | behave in
this way. Another thing is that truly-funny package names are
likey to be extremely troublesome in file mode-lines. On the
other hand, presently (INTERN "FOO" (PKG-CREATE-PACKAGE "()"))
prints out as |()|:FOO so for completeness I'd have to go along
with it.