Fuelclient refactoring

fuelclient provides all needed functionality to user who wants to use cli tools for fuel management. Bug regardless of that fact internal structure of fuelclient is pretty complicated. The reason for this is lying in using of utilities that just simply doesn't feet in such large (relatively) project. The most vivid examples are own written formatter for displaying all needed data via console and part for instantiating http client and its further communication with REST nailgun interface.

Instead of we could use OS community best practices tools such as:
- requests python module for making http queries
- cliff framework and additional utilities built into it to remake system's components structure and interactions between them.

Also several parts of the structure need to be refactored.

These improvements will allow us to have more control over code base and reuse parts of the system in other places where it may be needed. And as result using community tools may attract outside contributors to fuelclient project.