Summary:Support/British English in Mediawiki messages

OPEN This issue is open, waiting for action

Mediawiki prefers American English. I've just found a couple of British words (see below). I don't know about the other projects here.

gerrit:261362 gerrit:261364 gerrit:261367 gerrit:261368 gerrit:261369 gerrit:262909 gerrit:265920 gerrit:265914