refactoring of tests for reducing compilation time

Submitted by Kristof Szabados

Description

It was noticed as a result of the last architectural refactoring of Titan's tests (https://www.eclipse.org/forums/index.php/t/1101912/) that moving from a strictly sequencial build, to a build that can be parallelized improves build performance ... and in the case of tests this results in faster response execution times and faster response from the CI system.

This work should be continued:

the encoding related tests (touched by that refactoring) should be divided into more and smaller files.
other parts of the regression tests should also be refactored in this spirit

These changes could improve productivity, as developers will be able to learn if their change broke something much faster.

Version: 7.1.0