Debian pkg

hello - first attempt at a github pull request so i hope i'm doing this all properly.  i've updated the debian/rules file, removed a no-longer-extant file from the libessentia-dev list, and updated the changelog.  i also found a typo in src/python/essentia/plotting.py that prevented the pkg from installing properly ("pycentral: pycentral pkginstall: error byte-compiling files")