add assert, 0.0.24

simplify even more by making VAE required and inferring the number of…

… image tokens and image sequence length off the VAE

fix generation and further cleanup by moving generate method into Dal…

…le class

make sure generation is done in eval mode, and sets it back to origin…

…al state

use state of the art vision transformer in CLIP - 0.0.18

make sure last token can still predict eos

allow for transparent images