8.19.0

config: changes after bintray deploy
config: release 8.19.0
Rely on the column char index to find correct marker start
#145 Update to Checkstyle 8.19
minor: update on who is contributing to sevntu project
Hint with rule name for suppression
config: remove oracle installer
Update jfreechart library
upgrade tycho to 1.4
avoid NPE in rule filter (fixes #153)
Add documentation for "files older than a day" filter
fix typos and whitespace in metadata
Focus name field in configuration editor
Select newly created configurations
Remove unused properties file
minor: extend readme with details on how to install specific version from update site