Update MemriseForgiveTypos.user.js

This version checks alternative responses before displaying the popup warning.  For instance, if I type in "barbecue" in this test level, v0.1.7 will first warn me of a typo, then accept the response.  v0.1.8 will accept "barbecue" the first time.
http://www.memrise.com/course/12350/executive-mandarin/66

handleChinese() & handleFrench() still need to be fixed.