FloorfieldRouter: Inside/Outside and Subroom Recognition. Calculation only inside of rooms

GridCode knows the inside of rooms. Trialpoints on both sides of one door are checked with boost::within and the inside Point is used to start a wave, marking the inside of a room. Ending at walls/doors.

A new grid is created, holding the Subroom Ptr of the corresponding subroom. Pedestrians can always ask the grid, in which subroom they are. (Feature is not used yet in codebase)