Small Greek Letter MU and the scientific Micro Sign look alike

See thread - subject "[Fontforge-users] Character Glyph questions",
2014jan7 where it was noted that the two characters look alike.
http://sourceforge.net/mailarchive/message.php?msg_id=31817487
Merge pull request #1101 from JoesCat/micro_sign

Small Greek Letter MU and the Scientific Micro Sign look alike