[IO] BOOST_VERSION is defined only with version.hpp.

Otherwise it is undefined and the BOOST_VERSION preprocessor
condition took the first branch.
Merge pull request #466 from endJunction/BugfixBoostVersion

[IO] BOOST_VERSION is defined only with version.hpp.
Moved doxygen related files to Documentation/ and removed old script files.

The setup and corresponding scripts in base are not up-to-date since some time.
Use the devguide guide instead: http://docs.opengeosys.org/docs/devguide
Merge pull request #468 from bilke/scripts-cleanup

scripts-folder cleanup
Require minimum gcc version to be 4.8.

This version supports all of the used c++11 features.
Install GCC 4.8.1 on travis.

Instructions taken from http://askubuntu.com/questions/271388/how-to-install-gcc-4-8
Remove/Comment ProjectData related changes.

The ProcessInfo and the boundary conditions are changing.
The FEMCondition's are depricated.

We change to variable-centred initial and boundary
conditions.
Remove FEMCondition and its BoostXml reader.
[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.