Servo now supports several new web platform features:

• < source> in < video> and < audio> (@tharkum, #39717)
• CompressionStream and DecompressionStream (@kkoyung, #39658)
• fetchLater() (@TimvdLippe, #39547)
• Document.parseHTMLUnsafe() (@lukewarlow, #40246)
• the which property on UIEvent (@Taym95, #40109)
• the relatedTarget property on…