improvments to csa

1. syn and ant functions

(syn rich wealthy)
(ant rich poor)
(syn rich (not poor))
(syn rich (well off))

builds list of ((replacement object) (replacement object))
for example: ((rich wealthy) (rich (not poor)) (rich (well off)))
only attempts table lookup if it could not find major/minor props
does a recursive sequential list search

2. single atom subject universal assumption

if the left of are is a single atom, then assume quantifier is ALL
as in 'socrates is a mortal'


3. file functions

(read_syl file)     ; read in a syllogism from file
(read_syn file)     ; read synonym list from file
(read_ant file)     ; read antonym list from file