make :align easier to use

[kin-cho]

Hi, thanks for a great package, but I find :align hard to use. Can :align be supported so something like the following can work?

(ctbl:popup-table-buffer-easy '((1 2 3 4) (5 6 7 8) (9 10 11 12)) `("" ,(make-ctbl:cmodel :title "aaa" :align 'center) bbb ccc ddd))