Send proper content types when serving JPGs, PNGs and stylesheets.
Send proper content types when serving JPGs, PNGs and stylesheets.

The send-static fn in the browser repl tries to detect the content
type of a file by it's pathname extension. This patch adds support for
JPGs, PNGs and stylesheets as well. Without proper content type Chrome
and Firefox are refusing to apply stylesheets.

mstang/clojurescript,mstang/clojurescript,mstang/clojurescript