(album-write-html): Change order of argument.

(album-write-html): Change order of argument.
(album-convert-image): Likewise; add QVGA grade.
(album-convert-images): Change order of argument; don't use &rest for
`source-images'; change arguments `image-url-prefix', `html-dest-dir'
and `lang' to optional; add new optional arguments `title' and
`parent-url'.
(album-make-thumbnails): Change order of argument; add new optional
arguments `title' and `parent-url'.
(album-convert-directory): Change order of argument; use &optional
instead of &rest for `patterns'; change arguments `image-url-prefix',
`html-dest-dir' and `lang' to optional; add new optional arguments
`title' and `parent-url'.