Integrated Flowplayer Free and added testbed files

Replaced Flowplayer Commercial elements with Flowplayer Free.

Added experimental testbed files to allow more feature-testing and
flexibility.
Updated notepad CSS

Standardized notepad CSS for save/load top toolbar.
Added Summernote attribution to notepad window.

Changes undocumented from previous commit:
Changed notepad to open in a popup style window (no more pesky bookmarks
or URL!).
Changed save/load menu style to a tabbed format.
Reorganized repository structure

- Renamed subfolder "harvard-lecture-helper" to "main"
- Copied changes made in testbed to main