Deprecate Intersection::codimension and Intersection::dimension
At the 2015 dev meeting we decided to deprecated and eventually remove the two exported numbers Intersection::codimension and Intersection::dimension. The main reasons where the a) they are redundant and b) having Intersection::dimension denote the grid(!) dimension confused too many people. (see http://users.dune-project.org/projects/dune-developer-meeting-2015/wiki/Protocol Section 7.5.1.5 for the minutes of that discussion).
This patch deprecates the two numbers. I tested it with clang-3.6.2 (where it works) and gcc 5.3.1 (where it doesn't, but at least it doesn't break anything).
I plan to leave this open until monday 29.3. to give everybody a last chance for objections, and then merge it myself.