remove deprecated platform specific wrapper 'nexus' scripts

Consider removing all ./bin/jsw/<platform>/nexus(.bat) scripts.

Users should use ./bin/nexus(.bat) instead.

• handle version specific references in any ITs gracefully ( not sure this is impacted )
• release note
• leave <action>-nexus.bat in place, to allow for their use case to remain ie. clicking on with mouse to perform the single action.