losing 1.2 and 1.3 compatibility, but gaining 1.6
header-map implementation

wrap-lower-case-headers is still here, but it's not wired up anymore

:raw-headers, however, is removed. headers are always available in
whatever case you'd like.
use newer type hinting syntax
def allows docstrings, and newer syntax for integration tests
jetty, be quiet

sadly we can't shut it up completely (via this approach), but this
improves things significantly
:use -> :require

and sort :requires alphabetically
clean up sleeps

speeds up a lein all test :all by 25 seconds on my box
base-req consistency
test for with-middleware and *current-middleware*

also, stop with-middleware from evaluating middleware twice
Merge branch 'pr/184'
Update changelog