vl_test

* scalars frontend basically done

* frontend rename common/fun to util

* init logdir runs tags and scalars interface

* add debug

* add one mock data

* add dir server

* move frontend to server

* optimizer python package

* add mock data

* add back result encode

* use application/json as Response type

* rm .DS_Store

* update mock tags

* update mock data

* add third_party and refactoring cmake

* support pybind

* fix build error

* add storage_proto as dependency

* update gflags

* update comment

Server with frontend files