not handed over yet
don't close underlying RemoteFile when closing streams of that file - reverts f34667521d4c82fbfc2588c74972ad4d6d0e6e45
some small tweaks to PKCS8KeyFile in relation to the PEMReader -> PEMParser transition
get rid of over-zealous sending of channel EOF & close messages which was implemented with questionable synchronization

fixes #105

also relevant to #126 since AbstractChannel does not synchronize on
'this' anymore