Ubuntu package installs additional files that are not cleaned up on package removal

The `dragonfire_1.0.1_amd64.deb` package both depends upon several Ubuntu-packaged Python libraries and installs a number of Python packages directly from pypi in `/usr/local/`. When the dragonfire is uninstalled, the latter are not removed. Moreover, when nltk is installed as one of the dependencies, an `nltk_data` directory is created in one's home directory that is owned by root. From a package management perspective, it would be preferable to include all files required by dragonfire in the deb file and ensure that no extraneous root-owned files/directories are created outside of the OS directory tree so that the package can be cleanly removed.