Move demo app to sample data repos

[vpicavet]

It is currently broken.

The idea would be that all demos use by default a prebuilt version of iTowns, available at itowns.github.io/itowns, which is the gh_pages branch of itowns.

As for now the prebuilt lib should be manually pushed to the repo. Afterwards we can setup auto-build & push on new release tag.

To solve the current situation, it seems like we need :

• a new itowns build in the gh_pages branch with latest addition from mbredif ( #10 )
• update index.html for both demos in the sample data repos

@tbroyer sounds right ? Could you push the new build ?

[tbroyer]

1. pushed dist/itowns.js to gh-pages (removed everything else)
2. moved index.html to itowns-sample-data repository with inlined DemoUI.js and linking to "local data" (note: I had to slightly change/fix the build to avoid bundling jQuery, but that means you now need to load jQuery before you load iTowns, as with many other libraries that depend on jQuery; maybe we should do the same with Three.js BTW, but that's another story)
3. copied the index.html into itowns.github.io as v1demo.html, using data from itowns-sample-data and images from itowns-sample-data-small, and updated the site to load that file instead of the previous demo from this repo's gh-pages.

I also updated the index.html in itowns-sample-data-small even though it's currently broken (it was already broken anyway)

Next step is to update the README and the website.

[mbredif]

Fyi, the itowns-sample-data-small demo is now fixed.