SES-1764 New Workbench client-side and server-side protections to allow most functionality with long queries.

* query.js: More intelligent restriction on URL length limit; switched AJAX call to use form body, except
            for overwrite parameter, re-wrote AJAX call to take advantage of jQuery library

* QueryServlet.java : Allow POST for 'exec' action again (the culprit behind the exception in the bug report);
                      Suppress storing the query in a cookie if it is beyond a certain size, otherwise the
                      code hits Tomcat's default 8k HTTP Header limit and throws a RuntimeException.

* TransformationServlet.java: Removed final modifier from service(HttpServletRequest, HttpServletResponse) to
                              enable the query cookie intercept in QueryServlet.

* saved-queries.xsl: Changed execute link to a button that POSTs the request. In order to retain the user's
                     ability to locally bookmark queries up to a certain length, a clickable bookmark icon is provided
                     next to the button with the GET version with query encoded in the URL. For queries too long to
                     do this, a striked circle is presented instead.
SES-1762 : Add JSONLDMode to specify modes for parsers and writers
SES-1762 : Add JSONLDSettings
SES-1762 : Add JSONLD_MODE to link to the modes from settings
SES-1762 : Fix description
Merged in dvisser/sesame/SES-1764 (pull request #90)

SES-1764 New Workbench client-side and server-side protections to allow most functionality with long queries.
Merged in ansell/sesame/SES-1762 (pull request #91)

SES-1762 : Add JSONLD settings