Removed obsolete download_xcsoar_tools.sh script

This has been replace with the `xcsoar` package
tests: Moved test to top folder

The tests are not part of the `skylines` module
flask: Removed unnecessary static_folder constructor parameter

We have the assets blueprint for that.
public: Moved to assets/static/
websetup: Moved bootstrapping code to tests.data
Merge pull request #164 from Turbo87/cleanup

Folder structure cleanup