${CMAKE_CURRENT_BINARY_DIR}/../BaseLib is not necessary anymore.

- moved ProjectData.* to Applications/ApplicationsLib
- removed Vrpn folder in DataExplorer

Unified mesh layer mapping

Related to #469.

Disable warning C4996 on MSVC

added a base class to MeshLayerMapper and LayeredVolume for handling basic functionality and class structure

reworked prims-layer-generation to work from top to bottom and prefer older (lower) layers in cases of conflicting information

This warning appears in std::fill_n and can be ignored.

[PL] GroundwaterFlow.h -> GroundwaterFlowProcess.h.

Fixed wrong support point index at start and end point.

Skeleton project data

Update gtest to 1.7

When giving a custom comparison in std::sort use < as operator (not <=).

geometry->geometrical_set, patch->geometry.

This fixes crashes in debug mode (especially in some tests) in which case the
runtime checks this rule and quits execution on violation.

Now all branches will be tested by Travis.

Require minimum gcc version to be 4.8.1.