Remove repetition of a paragraph.
Add introduction.
Add sections regarding test groups and methods.
Re-word Java and Eclipse sections.
Fix spelling mistakes.
merge dev_4_4 -D org -I include -E exclude: PR 559 (remind that model changes may affect IceMapper (rebased))
merge dev_4_4 -D org -I include -E exclude: PR 570 (Add group and test method execution doc (see #11677) (rebased onto dev_4_4))