generated sources see issue #227

In "pom.xml" and "VadereGui/pom.xml", use latest version of Maven's Mockito plugin to avoid mocking errors during unit test phase.

See:
- https://github.com/calypsonet/keyple-java/issues/443
- https://mvnrepository.com/artifact/org.mockito/mockito-core
- https://mvnrepository.com/artifact/org.mockito/mockito-all/1.9.5

Moved configuration of Maven's code coverage plugin "JaCoCo" from subprojects to top-level "pom.xml".

Replaced Git hooks by Git command in "VadereSimulator/pom.xml" to create "VadereSimulator/resources/current_commit_hash.txt".

refactoring of the module / package structure: potentialfield calculators are now in the module simulation and the module meshing requires the module utils which is again the module without dependencies. simulation depends on meshing

add a faster exp-implementation approximating exp, and a benchmark library called Java Microbenchmark Harness.

add a faster exp-implementation approximating exp, and a benchmark library called Java Microbenchmark Harness.