Client Code - Modularized

The client code is divided into two files:
1. MainInterface.py: The instantiation of the objects and the invocation
of required functions are performed in this file.
2. ClientClass.py: it contains two main classes:
a) GlobalVariables class: encapsulates all the constant rates and
values.
b) Client class: encapsulates all the necessary variables and functions
to communicate with the server to receive user commands. The operation
modes (e.g., exploration vs. driving) as well as their corresponding
velocity values are set by an instance of this class.

Note: The previous version of client code i.e., client.py can be found
in "\ClientCode_ver1" folder.