@jbenet @whyrusleeping @mappum

If we permit initialization in `ipfs daemon`, then we must ensure that
the node instantiated in `ipfs init` (to create the welcome file) shuts
down and releases resources.

Kept running into "resource temporarily unavailable". Discovered that it
was our cousins Jeff and Sanjay over at LevelDB Ave.

go-datastore doesn't expose Close() so I extended the TsDs interface and
submitted a patch.

License: MIT
Signed-off-by: Brian Tiger Chow <brian@perfmode.com>
Signed-off-by: Brian Tiger Chow <brian.holderchow@gmail.com>