Add boot mode commands to ribcl module
Add boot mode commands to ribcl module

This commit adds the following commands
to ribcl module:
 - get_current_boot_mode
 - get_pending_boot_mode
 - get_supported_boot_mode
 - set_pending_boot_mode
 - get_persistent_boot
 - set_persistent_boot

stackforge/proliantutils,ramineni/proliantutils,openstack/proliantutils