Other misc useful integrant helpers

[SevereOverfl0w]

A few things which seem potentially useful:

• restart - shorthand for (suspend) (resume) - skips the refresh
• (find-component :k) - shorthand for (find-derived-1 integrant.repl.state/system :k). Useful for defining REPL helpers like (defn db [] (find-component :db)) instead of having to code against the specific implementation in use (which could change!)