CloudStack: Values with wildcards will fail signature validation
CloudStack: Values with wildcards will fail signature validation

Thanks to a small bug in the request signer the signature will be invalid for any request with any value containing a wildcard.

Identical to https://github.com/apache/cloudstack-cloudmonkey/commit/38b68fbe0bf9a4bea1836bba55be57928ef74cee

Closes #846

mgogoulos/libcloud,StackPointCloud/libcloud,watermelo/libcloud,techhat/libcloud,Kami/libcloud,andrewsomething/libcloud,watermelo/libcloud,ZuluPro/libcloud,mgogoulos/libcloud,mgogoulos/libcloud,watermelo/libcloud,mistio/libcloud,ByteInternet/libcloud,ByteInternet/libcloud,iPlantCollaborativeOpenSource/libcloud,Scalr/libcloud,ZuluPro/libcloud,illfelder/libcloud,StackPointCloud/libcloud,Kami/libcloud,iPlantCollaborativeOpenSource/libcloud,techhat/libcloud,Kami/libcloud,vongazman/libcloud,iPlantCollaborativeOpenSource/libcloud,ZuluPro/libcloud,andrewsomething/libcloud,Scalr/libcloud,erjohnso/libcloud,pquentin/libcloud,t-tran/libcloud,vongazman/libcloud,pquentin/libcloud,andrewsomething/libcloud,illfelder/libcloud,Scalr/libcloud,mistio/libcloud,t-tran/libcloud,samuelchong/libcloud,techhat/libcloud,mistio/libcloud,apache/libcloud,erjohnso/libcloud,pquentin/libcloud,apache/libcloud,NexusIS/libcloud,ByteInternet/libcloud,vongazman/libcloud,samuelchong/libcloud,NexusIS/libcloud,erjohnso/libcloud,SecurityCompass/libcloud,SecurityCompass/libcloud,t-tran/libcloud,illfelder/libcloud,samuelchong/libcloud,apache/libcloud,StackPointCloud/libcloud,NexusIS/libcloud,SecurityCompass/libcloud