packaging: Setup.py added to install this tool

Reorganized codebase as a Python package and setup.py
is added to manage install.

LICENSE updated as BSD

cd <glusterfs-tools dir>
sudo python setup.py install

CLI tools available:
  1. glustervolumes - Gluster Volumes listing with lot of filters
     sudo glustervolumes --help to list available CLI options
  2. glusterdf - Gluster volumes usage information
     sudo glusterdf --help to list available CLI options

Signed-off-by: Aravinda VK <mail@aravindavk.in>