Replaces tabs with spaces

Here's a new patch. So, I simply replaces all tabs with spaces in src/ and plugins/ folders. I'm not really sure if it breaks something. But changing tabs with spaces probably can't do much damage.

I've also added `melonjs.sublime-project` file. Basically sublime will have to translate tabs to 4 spaces. Plus, I added some goodies. Now, the build process is included directly into sublime, so you don't have to open terminal to rebuild documentation and so on...

I also want to point out for the people using sublime, like me, that I really recommend installing the SublimeLinter plugin (from package control). It uses the `.jshintrc` file that I created in the last commit and gives real-time feedback based on the options. For example if you have forgotten a semicolon somewhere, the linter will automatically highlight the line.