Bug 746124 - cfx-js integration work

This is work is pool of changes required for integrating [cfx-js linker](https://github.com/Gozala/cfx-js)

With this changes inn and clone of [cfx-js](https://github.com/Gozala/cfx-js)  under `addon-sdk/cfx` all the tests pass both on cfx-py and node. In other words this how you test it:

```sh
cd addon-sdk
git clone git://github.com/Gozala/cfx-js.git cfx
cd cfx

cfx test
Using binary at '/Applications/Firefox.app/Contents/MacOS/firefox-bin'.
Using profile at '/var/folders/0z/nztt5n4d4kg7b43dg9nv_3fc0000gp/T/tmpitLfnV.mozrunner'.
Running tests on Firefox 15.0/Gecko 15.0 ({ec8030f7-c20a-464f-9b0e-13a3a9e97384}) under darwin/x86.
..............................................................
62 of 62 tests passed.
Total time: 3.451745 seconds
Program terminated successfully.


npm test
Running all tests:
..............................................................
Passed:62 Failed:0 Errors:0
```