adds a new .ini entry to enable/disable the logger

[shinobu]

This pull requests adds the log.enable into the config and changes the referring lines in the code from log.level checks to log.enable checks and adds the entry into the about page

[shinobu]

done in https://github.com/AKSW/Erfurt/pull/135 @white-gecko

[white-gecko]

executed tests rebased to develop (9c20df62b889955981bddaa846978fe55ca6de89)

• [x] manual review commits
• [x] manual check that log enable/disable works
• [x] check unit tests:
  • OK (86 tests, 154 assertions)
• [x] check integration tests virtuoso:
  • OK (45 tests, 229 assertions)
• [x] check integration tests mysql:
  • OK (45 tests, 229 assertions)
• [x] check extension tests:
  • OK (11 tests, 59 assertions)

[shinobu]

white-gecko did you chose the correct Erfurt version? The pr https://github.com/AKSW/Erfurt/pull/135 in Erfurt isnt merged yet either

*edit

I tested it locally and it does work for me The About page shows, that the logger is deactivated Setting the log.level to 7 and creating a knowledgebase/triple -> no logs Turning the Logger back on and doing the same -> logs