CORE-3770 handles case when ES is not initialized

Donkey now responds with common error ERR_CONFIG_INVALID when it detects
that Elastic Search as not been initialized or has not been started.
Switched to handling search exceptions the Donkey way

This included converting a mislabeled failure to an error.
Merge branch '1.8' into treefix
Merge branch 'dev' into 1.8
CORE-3929: switched from clojure.data.json to cheshire
Merge branch 'dev' into 1.8
CORE-3929: switched to iplant-clojure-commons version 1.4.0
Merge branch 'dev' into 1.8

Conflicts:
	src/donkey/user_info.clj
CORE-3928: updated the documentation for the /get-only-analysis-groups endpoint
CORE-4032: added proxy endpoints for the new tool request services
CORE-4032: added a secured endpoint that the UI can use to add user comments to a tool request
CORE-4031: modified Donkey to use clojure-commons.config
CORE-4031: began implementing the code to handle email messages and notifications for tool requests
CORE-4031: finished adding support for tool notifications
CORE-4031: removed some debugging code
CORE-4031: fixed a couple of problems with tool request notifications
CORE-4031: began reorganizing the Donkey documentation
CORE-4031: fixed the formatting of a sublist
CORE-4031: fixed the formatting of a sublist in the README, correctly this time (I hope)
CORE-4031: finished restructuring the documentation