interfaces/*.idl: distinguish in and out xcaps on xtreemfs_renew_capability,...

interfaces/*.idl: distinguish in and out xcaps on xtreemfs_renew_capability, moved OSDWriteResponse to mrc_osd_types

git-svn-id: https://xtreemfs.googlecode.com/svn/trunk@201 f8528748-c2c0-11dd-ba5c-d3b7c2b3b534