Merge branch 'release-0.1.0' into develop
text/json -> application/json
pass exception class and traceback to exception handlers
make it possible to add properties and methods at runtime
docstring for `expose`
e exception handler instead of binding in exception_dispatch

this makes everything a bit less ambiguous
replace internal uses of binding as well
replace `add_exception_handler` with `add_exception_handlers`

this is more consistant with the routing and dispatch modules
bumped version number to 0.2.0
Release 0.2.0

  * fix json mimetype
  * add property and method helpers to Application
  * more consistant exception handler api