Simplify the release process

Stop increasing the version in `package.json` after a release, do the change just before the next release.

Add a shell script for making the release in one step.

/to @3y3 please review
/cc @sam-github This is addressing your [comment from Jun 19](https://github.com/node-inspector/node-inspector/commit/79b1d60270e8b2364c2b45510928c442c4c41b78#commitcomment-6737390).
I am sorry to hear that you lost changes. Here is what I don't understand: when you say symlinked projects, then you should still should have the original source somewhere, right?

This is the usual npm way of working with dependent modules:

```
$ git clone .../node-inspector.git
$ git clone .../v8-debug.git
$ cd node-inspector
$ npm link ../v8-debug
```

It will create the following structure for you:

```
(root)
  node-inspector/
    node_modules/
      v8-debug -> ../../v8-debug

  v8-debug/
```

That way you can `rm -rf node_modules` and the local git clone of v8-debug is not affected at all.