Decentralized Zeshy digest dependencies.

Zeshy components may not declare Zeshy's user digest file to be
dependent on external paths by calling
add_zeshy_digest_dependency_path(), which "path/file/mime" and
"zsh/global" now do. Shifted "00-startup/05-global" to "zsh/global" and
renamed remaining "00-startup" subdirectories accordingly.
Uncommitted erroneously commited refuse.