1. Provides dom0 IPtables driver to implement the Provider firewall rules.
2. Existing libvirt code has been refactored to reduce the amount of duplicated code to a minimum
3. The three provider apis in ec2/admin.py file are now fixed the following way:
a. remove_external_address_block returned 'OK' on removing blocks which didn't exist. This is now fixed.
b. block_external_addresses raised exception earlier on duplicate network blocks. Now the exception is logged and failed status message is returned.
c. all the three provider apis now logs for invalid and improper inputs and return uniform (a dictionary ) and proper status messages for all cases.
4. appropriate unit tests added to cover the same
Change-Id: I27d83186f850423a6268947aed0c9a349d8f8d65
ca9cb46798