We add a function to cause krb5_storage's to be sync'd to their backing
store. For memory backed storages, this is a NOP. For files, it calls
fsync on the file descriptor.
store/fetch/seek, and also make the eof-code configurable
git-svn-id: svn://svn.h5l.se/heimdal/trunk/heimdal@10931 ec53bebd-3082-4978-b11e-865c3cabbd6b