Improved Jinja2 mode

Hi CodeMirror's community!

I use Brackets editor for my work and I started to use Jinja2 syntax highlighting but I noticed that it had very basic syntax logic. I hope you will like my improvements what I use now. I attach 2 images where you can check the differences (number is not number, variable is not variable, boolean is not boolean, "and" was found in "sand" etc... ).

New:
![jinja2_new](https://cloud.githubusercontent.com/assets/871634/2755427/5353a592-c968-11e3-9d3a-3c9d3afd14b0.png)

Old:
![jinja2_old](https://cloud.githubusercontent.com/assets/871634/2755428/5355428a-c968-11e3-951d-ea173ec639d2.png)