Add automation tests for node-webkit.

The automation can replace existing automatic tests in node-webkit.
This is fundmental framework enabling users to add mocha test cases in it.
All test cases are running in seperated process so the whole test would not be blocked if some test case hang.
Each test case would output separated report in file system. It becomes easier to check the test results.
It allows to either run all test cases in batch or run each of them individually.

How to:
Assume the current directory is in "automation" folder.
1, At first time, install the npm modules:
    $npm install
2, Run all test cases
    $node mocha_test.js
or simply call `run.sh` on Linux
3, Run individual test case
    $nw <appName>
or
    $quiet=false nw <appName>

The test reports will be generated under the "output" folder, sub folders named by timestamp would be generated under it.
Merge pull request #2695 from yejingfu/automation

Add automation tests for node-webkit.
[Automation] Add functions to create TCP server and create child process.

- Provide a util function createTCPServer() to create TCP & socket server. The server object should be released at the end of current process.
- Provide a util function spawnChildProcess() to spawn a child process by inputing an absolute path of the new process.
[Automation] Add test case "app-single-instance".
Add start_app test case
Add buff_from_string test case
Merge pull request #2708 from yejingfu/automation

More automation test case added.
Modify the method names of asserting test case result.

Provide new function to assert test result: assertRunningResult()
Add new test case "call_require_with_node-main_set"
Add new test case "calls_across_window"
Add new test case "chromedriver2_server"
Fix minor bug and add new test case "console"
Add new test case chromium-args
Merge pull request #2712 from yejingfu/automation

Automation
Add new test case "cookie_api"
Add new test "crash_dump"
add new test case "crashonreload"
add new test case "datapath"
add new test case "document_cookies"
add new test case "fast_open_and_close_devtools"