Added basic diff functional
Merge branch 'master' into diff
Merge branch 'master' into diff
added diff tool
checkstyle
Merge branch 'master' into diff

Conflicts:
	preparation/resources/SampleResource/SampleResource.py
	preparation/resources/SampleResource/__init__.py
implicit cast to str fixed
SampleResource
Merge remote-tracking branch 'origin/diff' into clean-definitions
Almost all found OCR problems are solved, some other too

Delete empty parentheses and 'in \s meaning'.
Solve problem with space before abbreviation.