Special:EditWatchlist/clear: use destructive button

Change-Id: Ic229c4cce391c9f432b4a98fd40a86c537609936
Add specialpages-group-developer i18n string

Per discussion at I0db24fcbc7c

Change-Id: I56f92ac8f6918a196b0c146f314eaf9a0508aceb
Merge "Special:EditWatchlist/clear: use destructive button"
Merge "Add specialpages-group-developer i18n string"