(TK-69) Add new webrouting example using compojure

Add a new webrouting example that adds a ring handler using
compojure that changes depending on the path it is given.
Update webrouting example and webrouting docs to use `this`
instead of `get-service` when using the webrouting service.
(TK-75) Make Gzip encoding configurable for the Jetty webserver

This commit adds an option to the webserver configuration,
`gzip-enable`, which can be used to control whether or not the webserver
would attempt to compress the response body using Gzip encoding.
Merge pull request #73 from fpringvaldsen/TK-69-new-example

(TK-69) Add new webrouting example using compojure
Merge pull request #77 from camlow325/feature/master/TK-75-make-gzip-encoding-configurable

(TK-75) Make Gzip encoding configurable for the Jetty webserver
Update CHANGELOG for 0.7.5 release
lein-release plugin: preparing 0.7.5 release
lein-release plugin: bumped version from 0.7.5 to 0.7.6-SNAPSHOT for next development cycle
(TK-71/74) Improve Webrouting error messages

Improve error messages in the Webrouting service when
a specified service or endpoint does not appear in the
webrouting configuration and when the :web-router-service
section of the TK configuration is absent.
(TK-71/74) Change to IllegalArgumentException

Change the IllegalStateException thrown in the init function
of the webrouting service to an IllegalArgumentException.
(PE-3366) Add link to testutils docs

Add a link to the testutils docs in the README.
Merge pull request #78 from fpringvaldsen/TK-71/74

(TK-71/74) Improve Webrouting error messages
(TK-47) Modify endpoint data structure

Modify the list of endpoints to be a map. Now, since an
endpoint can have multiple handlers registered on it,
each key in the map is an endpoint, with its value being a
vector of all the handlers registered at that endpoint.
(TK-54) Fix multiple default servers error message

Fix multiple default servers error message to be something
readable.
Merge pull request #79 from fpringvaldsen/PE-3366-testutils-link

(PE-3366) Add link to testutils docs
Merge pull request #81 from fpringvaldsen/TK-54-default-server-error

(TK-54) Fix multiple default servers error message
Merge pull request #80 from fpringvaldsen/TK-47

(TK-47) Modify endpoint data structure