driver: Added 'read_mac_addresses' method
cap/nic_mac_addresses: Added 'nic_mac_addresses' provider capability

This is required by 'configure_networks' guest capability for Windows guests (Vagrant >= 1.6.0)
synced_folder: use 'os_friendly_id' method
Use Machine#state wherever possible so we update the index
Added provider usability test
config: Added functional_psf to disable psf (Parallels Shared Folders)
synced_folder: added "disable" method, deprecate "prepare"
config: merge customizations properly [GH-118]
action: don't require valid config on destroy [mitchellh/vagrant#1629]
Don't provide SSH info if VM isn't running
action/network: set proper mac address on private network

Fixed the same error as mitchellh/vagrant#3588
Use special NOT_CREATED_ID if machine is not created
guest_cap: Added 'unmount_parallels_shared_folders' guest capabilities for Linux and Mac OS
Version bumped to 1.0.9.rc1
Unit tests modified