CR-5547 OPENIG-410 Update documented console log messages

git-svn-id: https://svn.forgerock.org/openig/trunk@777 dbb9e58e-28e6-4ce0-90e8-f11d9605b710
(CR-5558) Add an error message that can be displayed by the default router

Only a `404` status code was returned when something goes wrong, nothing was
actually printed on screen if you accessed OpenIG from a browser.

This change add a JSON content (still machine parseable) with a descriptive
error message that is displayed by browser, making the client aware that
something was wrong for any reason.

This change was triggered with fix for OPENIG-411, that had the side effect of
not propagating route's exception to the user anymore

git-svn-id: https://svn.forgerock.org/openig/trunk@778 dbb9e58e-28e6-4ce0-90e8-f11d9605b710
Clarify where "logSink" and "temporaryStorage" get default settings

Thanks to Jean-Charles for suggestions and review over IM.

git-svn-id: https://svn.forgerock.org/openig/trunk@779 dbb9e58e-28e6-4ce0-90e8-f11d9605b710