CLOUDSTACK-2623. Provide appropriate AWS EC2 error codes in error thrown by CS AWSAPI. Since CS has very few generic errorcode groups, in AWSAPI parse the response message and translate the CS error to AWS EC2 error code.
Provide support for the following error codes -
AuthFailure, DependencyViolation, IncorrectState, InvalidAMIID.NotFound, InvalidAttachment.NotFound, InvalidDevice.InUse, InvalidFilter, InvalidGroup.Duplicate, InvalidGroup.InUse, InvalidGroup.NotFound
InvalidInstanceID.NotFound, InvalidKeyPair.Duplicate, InvalidKeyPair.Format, InvalidKeyPair.NotFound, InvalidParameterCombinatio, InvalidParameterValue, InvalidPermission.Duplicate, InvalidPermission.Malformed
InvalidSnapshot.NotFound, InvalidVolume.NotFound, InvalidVolumeID.Duplicate, InvalidZone.NotFound, MissingParameter, UnsupportedOperation, SignatureDoesNotMatch, InternalError, AddressLimitExceeded, InstanceLimitExceeded
VolumeLimitExceeded, Unavailable, ResourceLimitExceeded

CLOUDSTACK-2624. Support ModifyInstanceAttribute API in AWSAPI.
2 AWS instance attributes will be supported, 'InstanceType' and 'UserData'
As per AWS EC2, to modify both the attributes, the instance must be stopped. If not throw 'IncorrectInstanceState' error
Add missing license headers