Merge branch 'private_testing' into geshi_features

* private_testing: (375 commits)
  make testing of inaccessible methods easier
  updated composer dependencies
  renamed ActionRouter::checkPermissions to checkPreconditions
  shortened new search configs
  Section edit: corrected pattern 'SEC_EDIT_PATTERN'
  fix regex character class. fixes #2301
  fix: switch extensions if stylesheet in style.ini doesn't exist
  refactor: rename and move function to set $JSINFO
  typo. capital P for class name
  fix: add missing global $ACT for $JSINFO
  refactor: use native json_encode for $JSINFO
  refactor: rename JSINFO.DOKU_UHN and JSINFO.DOKU_UHC
  refactor: extract $JSINFO initialization into tpl_ function
  refactor: rename dta and dtb parameters
  doc(search): parameter must be string or false
  doc(search): highlight is expected to be an array
  show adavanced tools with JavaScript only
  adjusted language files to remove outdated string
  removed sub header from all languages
  added aria attributes
  ...