#46 Fix the SQLiteCpp dependency

This fixes the SQLiteCpp submodule to work properly when cloning recursively. The checked out version is the current one (2.2.0), should a new version come out the submodule needs to be updated by pulling the submodule and creating a commit in the ID2T repository. Additionally, I updated the dependency-script to automatically initialize the submodule if not already done, so manual git usage is kept to a minimum.