fixed dependencies, bumped btapp.js to 0.3.0

Currently the project gives a lot of errors when checking out, mostly due to using the latest version of underscorejs.
underscorejs 1.5 breaks btappjs (bindAll requires arguments now...). I didn't manage to fix this, instead I reverted to an older version.

Dependencies are now loaded as submodules

jquery 1.7.1 -> 1.9.1
backbone (latest) -> 0.9.9
underscore (latest) -> 1.4.4
btapp 0.2.0 -> 0.3.0 (latest)
json2 (?) -> latest
humane (?) -> latest