Able to run venus run command with PhantomJS

[roelrz]

This pull request is in reference to the following issue: #290

When defining commands and command line options with commander (https://npmjs.org/package/commander), it seems like the default case that was added to support running tests without the "run" command seemed to trump all other commands defined in Venus.js.

I went ahead and defined the command for the default case in it's own if clause that would only be executed if no commands are defined (e.g., "init", "demo", "run").

With the change, I was able to run the following commands successfully:

venus init
venus demo
venus run -t examples/mocha/Greeter/specs/Greeter.spec.js
venus run -t examples/mocha/Greeter/specs/Greeter.spec.js -n
venus examples/mocha/Greeter/specs/Greeter.spec.js
venus examples/mocha/Greeter/specs/Greeter.spec.js -n

[roelrz]

I also added support to copy directories wholesale with @venus-resource annotation: #295

Let's say we have the following annotations at the top of a unit test:

/**
 * @venus-library mocha
 * @venus-resource data1.txt
 * @venus-resource foo/data2.txt
 * @venus-resource foo/bar/data3.txt
 * @venus-resource ../biz/data4.txt
 */

If the test is running on http://localhost:2013/venus-core/1, the resources will be available at the following URLs:

• http://localhost:2013/venus-core/sandbox/1/data1.txt
• http://localhost:2013/venus-core/sandbox/1/foo/data2.txt
• http://localhost:2013/venus-core/sandbox/1/foo/bar/data3.txt
• http://localhost:2013/venus-core/sandbox/1/biz/data4.txt