removeMeshElements tool supports now bounding box parameters
added bounding box checks and re-ordered params
removed cmake-entry and corrected extent-tests
Merge pull request #480 from TomFischer/SearchLength

Implementation of two different strategies for calculation of search length.
Merge pull request #490 from rinkk/RemoveElementsAABB

Bounding box support for removeMeshElements tool
corrected TCLAP param output for removeMeshElements-tool
[PL] Add mesh subset to initialize().
[PL] Initialize MeshSubsets and MeshComponentMap.
[PL] Rename mesh_items_all_nodes; items->subset.
[PL] Add destructor for GroundwaterFlowProcess.
[PL] Move mesh_component_map to class variables.

...from the initialize().
Also delete it in the dtor.
[PL] Add createDofMap() in Process.
[PL] Use number of node's DOF in createDOFMap().
[PL] Remove MeshComponentMap include from GW.
[PL] Add dof_map to GroundwaterFlow.
[PL] Empty solve().
[PL] Add empty GroundWaterflowFEM.
[PL] Add initialize debug message.
First OGS simulation main program.
[A] Remove QtXml dependency.