Bug 886830 - make perf can now test V8 (node) and SpiderMonkey (jsshell). r=gandalf
Bug 897899 - In Chrome, console.log and console.warn need to be bound to the console object
Bug 897034 - Improve discoverability of L20n, part 1

Split the main README in multiple files inside docs:
 - Add a second example with genitive to justify the more complex structure of
   brandName in Polish.
 - Invert JavaScript API and HTML bindings sections
 - Collapsed "Further reading" into JS API section, fix typo in JavaScript code
   (textConent -> textContent)

docs/build.md: add instructions to build l20n.js with node.js
docs/html.md: fix wrong line ending
docs/api: fix typo (textConent -> textContent)
Bug 897865 - Ctxdata should have an API for setting and unsetting values. r=gandalf

Introduce: ctx.updateData(ctxdata: Object)

Updates the context data which will be available to all entities in the context.
The `ctxdata` is an object which extends the context data per key and per level
of hierarchy.  In other words, the following two calls:

```javascript
ctx.updateData({ user: { name: "Bob" } });
ctx.updateData({ user: { gender: "masculine" } });
```

will make the internally-stored context data look like this:

```json
{
  "user" : {
    "name": "Bob",
    "gender": "masculine"
  }
}
```
Bug 896979 -  l20n should be able to localize elements outside of BODY. r=stas