SES-1750 Added RepositoryManager.isSafeToRemove(String), and code that uses it in Sesame Console.

* Added some test code for the Drop command.
* Removed some boilerplate empty javadoc
SES-1750 Workbench now uses RepositoryManager.isSafeToRemove() to warn the user of unsafe deletions.
Merge branch 'master' into SES-1750
SES-1019 : Add BasicQueryWriterSettings.JSONP_CALLBACK
SES-1019 : Add stub support for JSONP_CALLBACK in SPARQLJSONWriterBase
SES-1019 : Add JSON Results support for JSONP callbacks and
prettyprinting
SES-1019 : Add compliance test for JSONP callback functionality
SES-1019 : Change default value for callback to sesamecallback to easily
identify where it comes from if it happens to be used
SES-1019 : Integrate JSONP callback into workbench in BaseServlet
SES-1019 : Switch to using regex pattern matching for validating
javascript function name
SES-1019 : Add jsonp settings to default properties
SES-1019 : Enable support for configuring JSONP support in workbench

If JSONP support is disabled then the function wrapper will never be
added, even if the callback parameter is setup.
SES-1019 : Add application/json and .json to SPARQL Results JSON
SES-1019 : Support application/javascript for workbench queries

It does not make sense to support application/javascript in
TupleQueryResultFormat.JSON, as it does not identify the format. JSONP
is only an encapsulation layer, and as such is only supported by the
workbench.
SES-1019 : Realistic valid callback name in test
SES-1019 : Simplify check on JSONP enabled property
Merged in ansell/sesame/SES-1019 (pull request #81)

SES-1019 : Add support for JSONP in the SPARQL Results JSON writer and the workbench
Merged in dvisser/sesame/SES-1750 (pull request #94)

SES-1750 Add safeguards against accidentally deleting members of a local federation