#+FOO:BAR

[Kent M Pitman <KMP@STONY-BROOK.SCRC.Symbolics.COM>]

We need to rule on whether people can say:
 #+FOO:BAR
 #+(AND FOO:BAR ...)
if FOO is a potentially non-existent package and/or BAR is a
potentially non-exported symbol. My feeling is that in both
cases, these should be treated as "failing" features but should
not signal read errors.

There are other things that should be resolved about #+/#-, too.
Such as what package it defaultly reads in, whether there are any
standard features we can all agree on which should be in some known
package, etc.