More modularization (#2)

- Renamed multi-unit file names to camelCase as described in [Scala style guide]
(http://docs.scala-lang.org/style/files.html#multiunit_files).
- Made `view.scala` as separate file.
- WIP: Moved implicit conversions in `package.scala` into `implicits.scala`.
- Generate all widgets by specifying just package, not each class.