[JS] improve mvn build process
[JS] improve mvn build process

* do not install node modules twice
* run npm install independently from profile "create-mqtt-module"
* npm install is always required for browserify
* do not install unnecessary dependencies if tests are skipped
* use npm option --ignore-scripts if tests are skipped to speed
  up the build

Change-Id: I2fcb712ca509259829e7a6ef431ba0c7ac2e6e43

bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr,bmwcarit/joynr