Catkinized iai_maps and adapted it to the new version of KnowRob

As discussed in https://github.com/code-iai/iai_maps/issues/4, I have split iai_maps into three packages such that each of them contains only one kind of map. All three packages have been catkinized. I have left all .launch files in iai_maps so that you don't have to adapt launch files that may include them.

The changes in detail: 
  * iai_maps: 2D maps for localization -> formerly subfolders 'maps', 'launch'
  * iai_kitchen_defs: URDF model of the kitchen -> formerly subfolders 'defs', 'room', 'Media'
  * iai_semantic_map: Semantic OWL map of the kitchen -> formerly subfolders 'prolog', 'owl'

**One issue to be considered:** The semantic map has been converted to the format used in the new, catkinized KnowRob. It's mostly the same, only some package names of dependencies have changed, and you can now load OWL files using package://-style URLs. However, this means that after merging this pull request, all of us will have to switch to the new KnowRob version.

I'd therefore propose to first test if everything works for those of you who use KnowRob and iai_maps (probably mostly Jan) using this fork.