Add s3ql package

S3QL is a file system that stores all its data online using storage
services like Google Storage, Amazon S3, or OpenStack. S3QL effectively
provides a hard disk of dynamic, infinite capacity that can be accessed
from any computer with internet access running Linux, FreeBSD or OS-X.

pkgs/tools/backup/s3ql/default.nix

@@ -0,0 +1,23 @@
+{ stdenv, fetchurl, python3Packages, sqlite  }:
+
+python3Packages.buildPythonPackage rec {
+  name = "${pname}-${version}";
+  pname = "s3ql";
+  version = "2.13";
+
+  src = fetchurl {
+    url = "https://bitbucket.org/nikratio/${pname}/downloads/${name}.tar.bz2";
+    sha256 = "0bxps1iq0rv7bg2b8mys6zyjp912knm6zmafhid1jhsv3xyby4my";
+  };
+
+  propagatedBuildInputs = with python3Packages;
+    [ sqlite apsw pycrypto requests defusedxml dugong llfuse ];
+
+  meta = with stdenv.lib; {
+    description = "A full-featured file system for online data storage";
+    homepage = "https://bitbucket.org/nikratio/s3ql";
+    license = licenses.gpl3;
+    maintainers = with maintainers; [ rushmorem ];
+    platforms = platforms.unix;
+  };
+}