MDL-38239 gradebook: Importing grades from a .txt file with commas for decimals causes an error
MDL-33719 When overwriting a file the filemanager is not refreshed
MDL-39177 File reference is not updated when overwriting the file
MDL-39177 Original info is not preserved when overwriting a file in filemanager

original file location is used by filemanager to indicate that file is a source of reference and file the list of referencing files
MDL-39177 Discard file origin when moving/renaming a file in filemanager

Created one function that handles file update to be used from both JS and nonJS filepicker
MDL-39177 Update file in filearea only if original is present

Now when file was deleted in filemanager and new file with the same file was uploaded the references will be converted to copies exactly like UI warns in filemanager.
Also do not delete original information from draftfiles.
MDL-39177 Remove code duplication
MDL-39177 Perform all checks on draftfile area before saving the files
MDL-39177 Ensure files are overwritten correctly on unzip
MDL-39177 New function file_storage::get_unused_dirname()
MDL-39177 More comments about confusing files.source field
MDL-39177 Updating userid when file is overwritten
Merge branch 'MDL-39697-M25' of git://github.com/lazydaisy/moodle into MOODLE_25_STABLE
MDL-36482 Fix slipped error, thanks Petr!
MDL-39768 behat: Adding focused panels CSS selector
Automatically generated installer lang files
MDL-39177 make sure we don't remove existing directories when cleaning up unzip
MDL-39456 cachestore_file: added reference to global $CFG

By holding onto a reference of the global $CFG object we
can be sure that it isn't destroyed before we are done
with it.
This allows for caches to be used within destructors for
purposes such as delayed writes.
Merge branch 'install_25_STABLE' of git://git.moodle.cz/moodle-install into MOODLE_25_STABLE
weekly release 2.5+