* fix RecordEvent interface

* modify default level to 4

* update interface use

* add const default trace level

* update record event interface using

* update record event interface using

* update operator.cc

* update part2

* update part1

* fix include profiler.h header in ps server

* fix include profiler.h header in ps server

* fix profiler.h header

Add basic Cost Model, it uses executor to run program and profile it to get op time.

This is an early basic version, we will add more functions in the future.