feat: Added/Updated benchmark problems (preliminary)

The commited code is still in a preliminary state and missing proper
documentation and test cases, so handle everything with care.

There is now a specialised (but still marked as abstract) class called
BechnmarkProblem to provide methods for reocurring calculations within
many benchmark problems. It also defines boundaries and the
shift/rotation of fitness landscapes according to the Real-Parameter
Black-Box Optimization Benchmark 2013 from INRIA.

Addition of the following benchmark problems, based on the
Real-Parameter Black-Box Optimization Benchmark 2013.
- Attrachtive Sector Function
- Bent Cigar Function
- Büche-Rastrigin Function
- Discus Function
- Ellipsoidal Function, rotated
- Step Ellipsoidal Function

Updated the following problems based on the new abstract class
BenchmarkProblem
- Ellipsoidal Function
- Linear Slope
- Rastrigin Function
- Sphere Function

Signed-off-by: Sebastian Niemann <niemann@sra.uni-hannover.de>
feat: Added plot for 2D fitness functions

Added anew gnuplot script for ploting 2D fitness functions.

Signed-off-by: Sebastian Niemann <niemann@sra.uni-hannover.de>
devel: Added ArmadilloJava as dependency

Added the linear algebra library ArmadilloJava as a dependency to the
pom in order to avoid manually dependency handling.

Signed-off-by: Sebastian Niemann <niemann@sra.uni-hannover.de>
fix: Removed temporary files from gnuplot

Removed files generated for testing from the gnuplot folder.

Signed-off-by: Sebastian Niemann <niemann@sra.uni-hannover.de>
feat: Ignore data and image files within the gnuplot dir

Added all gnuplot/*.dat and gnuplot/*.png to be ignored, since these are
user generated files.

Signed-off-by: Sebastian Niemann <niemann@sra.uni-hannover.de>
fix: Removed unwanted files

Removed files that are added unser versioning per mistake. This
contains:
- Machine dependent files automatically added via Maven
- Eclipse specific .project file
- Eclipse specific .setting folder and all files inside
- Eclipse specific .classpath file

Signed-off-by: Sebastian Niemann <niemann@sra.uni-hannover.de>
fix: Ignore autom. added machine dependent files

Set git to ignore windows libraries (DLL-Files) that are automatically
added by Maven.

Signed-off-by: Sebastian Niemann <niemann@sra.uni-hannover.de>