split change

[Paul Haahr <haahr@mv.us.adobe.com>]

i retract my blessing, at least for the change in its current version.
the functionality will be included 0.7, but the proposed implementation
is incorrect, in the case of ready from backquote with null ifs, which
is done all the time.  in the future, %fsplit will do the character
by character splitting if given '' for the separator, but %split will
continue to do exactly the same thing as backquotes.

sorry for the confusion,
paul