fix(embed): embed jquery target is now searched for instead of assuming last class
Merge pull request #6796 from beck24/embed_js

fix(embed): embed jquery target is now searched for instead of assuming last class
fix(messages): use recipient's language in the notification

Fixes #6902
Merge pull request #7189 from Elgg/message_notification_language

fix(messages): use recipient's language in the notification
chore(docs): fix variable reference

 array passed to elgg_define_js() is expected to have a 'src' key, not a 'path' key
Merge pull request #7190 from hypeJunction/docs

chore(docs): fix variable reference
fix(i18n): system cache now supports regional designators in language codes

Name of a cached language file can now have the following structure:
 - language code (2-3 lowercase alphabets)
 - underscore followed by regional designator (2 lowercase alphabets)

Fixes #7187
Merge pull request #7192 from juho-jaakkola/language_codes

System cache should support regional designators in language codes
chore(release): merge 1.8 branch
Merge pull request #7195 from juho-jaakkola/merge_18

Merge 1.8 into 1.9
chore(i18n): update translations
chore(release): v1.9.0
Merge pull request #7196 from juho-jaakkola/release-1.9.0

Release 1.9.0
fix(upgrade): fixes erronous values in the list of processed upgrades

Both the upgrade file name and the class responsible for the actual upgrade logic had been set as the
value of variable called $upgrade. This mistake may have caused the class to be saved to the list of
processed upgrade instead of the filename. This upgrade replaces the class with the filename.

Fixes #7198