building warning is not obvious

[tiye]

With configs like:

{:id :dev
  :target :browser
  :modules {:main-dev {:entries [client.main]}}
  :public-dir "dist/dev/"
  :public-path "/dev/"
  :devtools {:after-load client.main/on-jsload!}}

Can read real warnings from the message:

[thheller]

I usually only look at the compile output for warning but that was also broken and not printing there. Will release soon.