Revert dataclasses based replacement for devicedependent

There is a big problem with this commit - it only works with:

* Python 3.5 and later due to
  type hints being introduced with
  PEP-484 https://www.python.org/dev/peps/pep-0484/
  lead to syntax errors on earlier versions.
* (even worse) only with Python 3.6+ due to
  PEP 526 variable annotations (introduced in 3.6)
  needed by dataclasses too.

We aim, however, at Python 2.7 compatibility with this project.

So after all, I reverse the commit and will implement the changes
in a different way.

setup.py

@@ -43,9 +43,6 @@ setup(name='brother_ql',
           "packbits",
           "pillow>=3.3.0",
           "pyusb",
-          'dataclasses;python_version<"3.7"',
-          'typing;python_version<"3.5"',
-          'enum34;python_version<"3.4"',
       ],
       extras_require = {
           #'brother_ql_analyse':  ["matplotlib",],