Update everything

I updated old code and added new feature. 
* More recent version of SQLite (3.8.4)
* Compiled to asm.js (should be faster, at least on firefox)
* Changed API. Results now have the form <code>[{'columns':[], values:[]}]</code>
* Improved GUI of the demo. It now has :
  * syntax highlighting
  * nice HTML tables to display results
  * ability to load and save sqlite database files

If you want to merge only some changes, I can make several distinct pull requests.