Introduce dispatch.php for REST-style endpoints

Adrian Heinerequested to merge
adrian-httpDoYouSpeakIt into master

See foodsharing-dev/issues#83. This commit takes two shortcuts:

  1. Instead of actually using nice URLs, this goes through a new entry point dispatch.php. Server config needs to be changed before we can use nice URLs for this.
  2. I created a really nice structure with PHP namespaces and everything, but it just forwards to the old stuff.

Merge request reports