* enhance the app development experience - you can look up the
method introduction right inside the code without searching
via git blame
* easier to write apps for multiple versions
add logSettingsController
add download logfile button
move getEntries to LogSettingsController
move set log level to logsettingscontroller.php
add warning if logfile is bigger than 100MB
add unit test for set log level
fix typecasting, add new line at EoF
show log and logfile download only if log_type is set to owncloud
add unit test for getFilenameForDownload