Insert composer

This PR replaces the custom vendors and autoloaders, and introduces composer to the web2 application.
In order to make this repository consistent with the API repository have I committed the vendors folder as @akrabat informed me that packagist is not available during deployment.

Tips for the code reviewer:

- This PR is based off the changes introduced in #113; basing this off of master would introduce a lot of merge conflicts for no apparent gain. I advice that #113 should be merged or rejected first. In the latter case this PR should be changed.
- Don't open the changes tab or commit #4feb0f3; these contain the replaced vendor folder changes ONLY and will probably kill your browser if you try to. Github does not approve of this many inserts and deletes.
- I have purposefully divided this PR into 3 commits; the first introduces composer, the second replaces the vendor folder, and the latter rewires the application.