remove imageLoaded()

in favor of incremental loaded callbacks
Incremental behavior

Imagesloaded is no longer required; instead we bind load behavior to
each fluidbox image.
Fix an error with resize behavior

was bound to a[data-fluidbox] which I believe is either vestigial or
conventional to original author’s code. Instead specify a selector that
matches explicit class assignments int this module, so it should work
more universally.
clean up