Handling issue #52

Many consumers of the compute service uses 'OS-EXT-IPS:type' field,
which is easy to support as SL always assigns private
(primaryBackendIpAddress) and public (primaryIpAddress) IPs which can be
categorized into 'fixed' and 'public' respectively.
Fixed public ip type

Public IP is known as floating IP in OpenStack changed public type to
floating.
Made primaryIpAddress as fixed.

The primaryIpAddress is static and doesn't change during its life-cycle,
it was more appropriate to keep it as 'fixed' instead of 'floating'. The
portable IP from SoftLayer makes more sense for 'floating' IP.
Merge branch 'master' into ip.type
Merge pull request #53 from amol/ip.type

Handling issue #52