Revert "Makefile: name binary ceph-filestore-dump"

This reverts commit f0b2e32af69d7d009837832066a1445c45bbc362.

Be consistent with everything else.
.gitignore: fix ceph_filestore_dump name

Underscores!

Signed-off-by: Sage Weil <sage@inktank.com>
msg/Messenger: do not crash on unhandled message

This is just polite.

Signed-off-by: Sage Weil <sage@inktank.com>