added server metadata operations for Fog::Compute::RackspaceV2
refactored Fog::Compute::RackspaceV2 metadata to take collection as a parameter rather than using it as part of the method name.
fixing broken metadata tests
changed metadata implementation for Fog::Compute::RackspaceV2::Server and Fog::Compute::RackspaceV2::Image
changing variable names to make code clearer
fixing broken tests
Merge branch 'master' of github.com:fog/fog into server_metadata
added better acceptance criteria to server/image metadata tests; added metadata to ignored_attributes to address bug
[xenserver] added missing HostCpu model
[xenserver] added missing host_cpus attribute to Host model
[xenserver|tests] added HostCpu model tests
[xenserver|tests] typo fix
[xenserver|tests] test Host.host_cpus method
[xenserver] add missing Host attributes (edition, software_version)
[xenserver] replace #connection with #service in models

connection is now deprecated as per #1415, #1392
fixing merge issues with master
fixing typo
fixing broken tests
[rackspace|compute] updated rebuild to support passing additional options
Fix typo and use #get_header to handle mixed-case header keys