Move build system from gyp to gulp

[romandev]

I'm submitting a ...

• bug report
• feature request
• support request

General infomration

Description

We need a new build system instead of gyp build system that is too complex.
The gulp build system is very popular in Node.js, and it's a good alternative to us because it's very simple and easy to use.

Context (Environment)

Operating System

• Linux (x86/x64)
• OSX (x86/x64)
• Windows (x86/x64)

[nadongguri]

Wow, already merged to master. 👍