Refactored the Central logger.

CentralLogger no longer `from pydzen import config`. This way pydzen can
import CentralLogger and Logger in a timely manner.
Dynamic pathing support.

Instead of using the `HOME` environmental variable and appending
`./pydzen` to set the pydzen folder, pydzen now uses `os.getcwd()` so
that pydzen can be run in any folder and still work correctly. Of course
this means that any scripts attempting to run pydzen will likely have to
`cd` into it's folder before doing so.
dzen now 3 processes for left, right, and center.

Splitting dzen into three scripts allows using dzen's alignment which is
much cleaner than having pydzen.py attempt to find the size of each
output.
Removed unused functions in utils.
Updated README with dependencies