Refactoring to a "single page application"-paradigm

**This is WIP, please do not merge, but feel free to add comments and wishes**

Since this little project seems to get quite large, I'm opening this PR early. This allows me to easily add a ToDo list for better planning and a better overview about the changes.

I will regularly rebase my branch to latest master. Also note, that this is only an experiment, and might be deleted without being merged. If you want to contribute or help me with this larger change, find me on IRC or drop me a mail.

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ToDo:

- [x] add index.html to serve the basic page
- [x] add JavaScript to load different apps defined as modules
- [ ] implement geomap module (WIP)
- [ ] implement graph module
- [ ] implement list module
- [x] choose standard/default module
- [ ] do something about the "remove this!!!" commit
- [ ] remove "old" code (all single html-files that are implemented as modules)
- [ ] take a look on mobile (smaller screen size)