Code cosmetics
Add implementation of a Singleton pattern
Improve Conf class

Inherit from "Singleton" and add more functionality to it.
Merge pull request #13 from bhedrich/refacor-conf-class

Refacor conf class
Remove unused method
Change Pyflakes requirement
Some cosmetics
Add GUI support

Use Tkinter for simple graphical user interface. Kivy,
GTK or QT are cooler, but too much.
Merge pull request #14 from bhedrich/add-gui-support

Add gui support
Update README
Bump version: 0.3.7 → 0.4.0
Add a nonce generator to the crypto module
Use unicode strings in "libkeepass" backend internally
Add support for PassIFox

To support PassIFox we need to implement the GetLoginsCountRequest
request.
Apply changes to the tests