scripts: When zotonic is not running, echo the output of erl_call

This is to ease debugging situations where Zotonic in fact *is*
running but erl_call thinks it isn't.
mod_development: When activating a module, call Module:manage_schema(install, Context).

This makes development life easier while developing a module's schema.
mod_development: Remove unused function; shorten compilation notification
scripts: Fix typo in zotonic-update