Merge branch 'sandbox'
changes in host installation and controller installation scripts
fixes
Update db.py

Table vm_config deleted
Update 0_constants.py

Constant VM_CONFIGURATION added
Update user_model.py

get_configuration_elem method updated
Adding python libvirt source code to repo
Merge branch 'master' of https://github.com/apoorvemohan/newbaadal
Merge branch 'master' into sandbox