IvyResolver should be M2 compatible if Resolver.mavenStylePatterns is used

The issue is that ohnosequences.ivy.S3Resolver is expected to create directory structure com/foo/bar for organisation 'com.foo.bar', otherwise it will not be compatible with maven. IvyResolver should be M2 compatible if Resolver.mavenStylePatterns is used. I tested it with sbt0.3 and it seems to work. This is a very simple change