Added support for parsing file-like objects with XML payloads

Ignore-this: 3820b270d80ba7240d94ae8da18591a5

darcs-hash:20100820110431-1e3d8-40903c2dcaf8907e1b8020b3430f1eb308229b09
Fixed parsing of IdentityMany policy elements

Ignore-this: e218e0f6c526eec6bae49162f6052b61

darcs-hash:20100824075003-1e3d8-abdf797ca094fc88257c1343a9d7a1b201ef9154