Added test changes that enable save/reload functionality to Level1.

These is just a sample as to what needs to be done to enable save/load to all levels (edits are trivial).

Note there is a reset button instead of the icon in GeoGebra, since it doesn't fire the proper events in JS, enabling the save part. This is most probably a bug in GeoGebra itself and I'll report it upstream at some point (you may do so, too).

Also, until they release a fix, probably there won't be another less ugly workaround to that problem.

The other differences are changing links from absolute to relative to enable local deployment (and make contributors' life way easier). Note absolute URLs won't stop someone who's determined to copy the game verbatim (as it took me 3 minutes to find and change), so it's of no effect overall.

If you accept this pull request, I'll send in another one or two, containing for example a .gitignore file (you have Thumbs.db in the files - a 'junk' Windows-specific file), exporting deployggb.js to an external server (will reduce codebase in current project which is always good) and other small fixes.

Please check out my suggestion in the 'Issues' section about migrating this to a Github page - will make things way easier as I try to prove there.

I'm licensing this commit under MIT license, giving you the liberty to use it in any way you want.
Note that you have accepted already contributions from other people, which makes the licensing situation of the project really complicated; not to mention the fact GeoGebra has a non-open-source license, so my earlier suggestion for choosing what license you'll use is now even more important.