Replaces .zsh_functions with functions/files

Adds `.zsh_sleep` to use the built-in Zsh select module (for sub-second
sleeps).

Culls a few of my less-used functions.
Adds `$api_env` `curl-api` var, `curl-api-login`

Makes it easier to switch environments for testing the API.
Fixes `with-fresh-test-db` to parse ERB
Prepends `curl-api` files with `api.`
Adds script used to fix `.zsh_functions`
Adds infrequently-used functions

... even though I never use them.  (Or they're for outdated
environments.)