jshint: Log jshint version to console

Similar to what PHPUnit does already.

Pushed:
mediawiki-core-jslint
mwext-AbuseFilter-jslint
mwext-ApiSandbox-jslint
mwext-Cite-jslint
mwext-Echo-jslint
mwext-EventLogging-jslint
mwext-MobileFrontend-jslint
mwext-TemplateData-jslint
mwext-Vector-jslint
mwext-VisualEditor-jslint
mwext-WikiEditor-jslint

Change-Id: I9be12a9e86677269a03aee436346d66308be2293