Added blanket.js for JS code coverage

Resolves #1625
UncoveringTheBlanket - Disabling blanket when running tests from command line.

When running tests from command line blanket has to be disabled otherwise QUnit.Start() will be called twice which causes a "global failure". Note that chutzpah has an option (/coverage switch) to collect code coverage and is using blanket (sic!) to do this.
DontPublicizeInternalAffairs - changing visibility of OnReconnecting from public to internal (fixes #3005)

OnReconnecting is not meant to be used by end users and therefore should not be public.