* default learning rate, temperary fix

* update

It's already fixed by Wuyi's PR, but his PR may take some time to
merge, but I want to get this change in ASAP.

Unchecked errors could be handled by: cd go; gometalinter --vendor --disable-all --enable errcheck $(glide nv)

Fix fetch record from master

* using etcd as fault tolerant training

* update

* workable version, ft not tested

* small fix

* update

* remove TODO

The buffer allocation size should be number of bytes, not number of
floats.

* Server recovery from checkpoint