use serve-static middleware and parseurl

connect has been split into separate middleware projects
we don't need to depend on the entire connect any more
we keep dev dependency on connect to allow for testing

fixes #5
check for .gzip presence on middleware init

No more fs.stat on each request
Drawback: won't serve compressed files if added after app starts. There
are plenty of others middleware that should handle that.

fixes #4
Release 0.3.0