[Tests] Removed TestBoostXmlCndInterface.

The test tested class BoostXmlCndInterface, that is removed previously.
Remove ProcessInfo class as well.
Implementation of IC/BC and ProcessVariable.
Empty GroundwaterFlowProcess and its Base classes.
[PL] Add ProcessLib to CMake files.
[Doc] Add ProcessLib to doxygen inputs.
[PL] Add virtual initialize().
[PL] Add number of node variables.

Element variables are not yet used.
[PL] Add destructor for GroundwaterFlowProcess.
Adjusted GUI for removed FEMCondition classes
Remove unused GeoInfo and FEMEnums classes.
[PL] Include class Process into ProjectData.
[ProjectData] Add vector for storing ProcessVariables.
[ProjectData] Make attribute name readable/consistent.
[ProjectData] Add configuration of project to ProjectData.
[ProjectData] Path argument for ProjectData constructor.
[ProjectData] Functionality to read geometry.
[ProjectData] Functionality to read mesh.
[ProjectData] Change deallocation order.

The processes first, because they depend on meshes; then the meshes.
[ProjectData] Add findMeshByName() as private.

This returns an iterator to the found mesh.
Two versions are required for the modifying and non-modifying algorithms.