Changed=true now reported on new volume.
Only detach volume when instance is specified as 'None' or '' rather than whenever instance is not specified at all
Fix regression caused by 6b27cdc where by no volume is created if id or Name is not supplied
Remove unnecessary empty aliases
Corrected example to use acceptable parameter for ions
Added exception handling to get_all_instances call
Moved the attachment state validation code to attach_volume function rather than create_volume function
Refactored attach_volume and detach_volume so that changed state can be passed back to call
Created get_volume_info function so that state=present and state=list can return the same data. Also added instance_id as a returned value in attachment_set dict
Updated aws connection method so that boto profile can be used
- removed import of sys module.
- HAS_BOTO constant to check if import was successful.
- trigger a failure when import fails.
- removed unnecessary imports.
