Replace dbus-python with pydbus

[SpotlightKid]

(For background, see #1)

If dbus-python is installed via the distribution's package system, you may get the following error when running jack-select:

pkg_resources.DistributionNotFound: The 'dbus-python' distribution was not found and is required by jack-select

This means that dbus-python does not register itself correctly as a setupotools compatible package.
Unfortunately this seems to be the case on most major Linux distributions. For example, thatswhy I patch the setup.py file to remove the explicit dbus-python dependency in my AUR package for jack-select.

The dbus-python package has been marked as outdated now, so we should switch to pydbus

[SpotlightKid]

Unfortunately, pydbus does not support asynchronous calls yet, so it is no viable replacement option until it does.