SSDM-274 : Javascript-based Microscopy Data Viewer - follow-up:

- split one big javascript file into separate files (one file per class) and use RequireJS to resolve the dependencies
- do not include Bootstrap in the webapp (add Bootstrap as a common openBIS javascript library)
- do not include openbis.js and openbis-screening.js (use existing common js files)
- do not pollute the global namespace with all the image viewer related javascript classes - expose only the main class

SVN: 31477