Iscsi Manager and CLI iSCCI Module

New iSCSI manager has been introduced to conveniently work with iSCSI
service provided by SofyLayer. Respective CLI module has also been
introduced for CLI interaction.
Incorporated suggested changes

corrected command listing style and divided iSCSI section and snapshot section.
Modified filter for ISCSI and snapshot Item price IDs
Improved the docopt docs with example, etc.
Using custom response inside tests

Fixure Product_Package has too many things which are not required by the iscsi tests. Using return_value from `mock` to test iscsi manager.
Merge branch 'master' into iscsi-manager
Adds an import test that imports all CLI modules to catch syntax errors and expose it as missing test coverage
Fix copy/paste errors
Print modules being imported (for easier debugging)
Added tests for help and summary CLI modules. Updated network CLI tests
Fixes copy/paste mistake, the best kind of mistake
Adds rwhois and sshkey CLI tests

* Fixes bug where updating rwhois would send fields you don't want updated
* Fixes bug where CLIAbort isn't raised whenever a user cancels deleting an sshkey
Merge pull request #302 from aparnapatil/iscsi-manager

Improves iscsi manager
Merge pull request #316 from sudorandom/test-all-CLI-modules

Adds test that imports all CLI modules
Add firewall support
Fix changes requested in comments
Remove camel case from method name
Change Delete to Cancel
Fix comment for cancel CLI
Add prefix for id to simplify the CLI