Fix expiration option to cbc-create

ingenthr-mbp:~ ingenthr$ date -r 2377067953
Sat Apr 29 00:39:13 PST 2045

ingenthr-mbp:~ ingenthr$ cbc create -e 2377067953 blah
something
Stored "blah" CAS:29940470145b0000

ingenthr-mbp:~ ingenthr$ cbc cat blah
"blah" Size:10 Flags:8daf2db1 CAS:29940470145b0000
something

ingenthr-mbp:~ ingenthr$ cbc stats "key blah 41"
127.0.0.1:11210	key_is_dirty	0
127.0.0.1:11210	key_exptime	0
127.0.0.1:11210	key_flags	2972561293
127.0.0.1:11210	key_cas	100143336821801
127.0.0.1:11210	key_vb_state	active

Change-Id: I245e743fa514dc29eb3e9422eae34aa6777ab8ef
Reviewed-on: http://review.couchbase.org/28426
Tested-by: Sergey Avseyev <sergey.avseyev@gmail.com>
Reviewed-by: Trond Norbye <trond.norbye@gmail.com>