(TK-44) Add webrouting docs

Add docs explaining how to use and configure the webrouting
service.
Ensure :default route-id specified

Using schema, ensure that a :default route-id is specified when
specifying multiple web-routes.
(TK-44) Add webrouting example

Add a webrouting example app to the documentation.
(TK-44) Add link to webrouting docs in README

Add a link to the webrouting docs in the main README file to make
it easy to find.
(TK-44) Add info about intent of Webrouting Service

Add information about the intent of the Webrouting Service to the
beginning of the webrouting-service.md file.
(TK-44) Improve wording in Webrouting description

Improve the wording of the description of the Webrouting Service
in the main README file.
(TK-48) Improve proxy request URI construction logic

Prior to this commit, the proxy URI request construction would
always add a slash to the URI.  In cases where this wasn't
necessary, it would cause failures.

This commit changes the implementation to use a constructor
from the Java URI class, and takes a bit more care to make sure
that we have slashes in the correct places in order to build
up the URI properly.
Merge pull request #53 from cprice404/bug/master/TK-48-url-leading-slash

(TK-48) Improve proxy request URI construction logic
Remove unused def

Remove a def that was never used anywhere in the code.
Merge pull request #46 from fpringvaldsen/TK-44-webrouting-docs

(TK-44) Webrouting Documentation
(TK-51) Move webrouting server info to config

Move the server info for each endpoint in the webrouting service
into the trapperkeeper configuration, rather than having the
user hardcode it when adding a handler with the webrouting
service.
(TK-51) Update docs and example with new config

Update docs and example for the webrouting service to reflect
the new configuration changes to the webrouting service.