test=release/1.2

Add group normalization operator.

* row_conv
* uniform_random
* layer_norm
* create_parameter
* hard_shrink
* ssd_loss

Do not use ctor

* Reduce line of codes.
* We can use virtual function for Maker now.
* The implementation does not care what maker holds, it is easier to
refactor later.

* script to add semicolon

* fix typo