[tex-k] More fancy-format typos in The METAFONTbook

[胡亚捷 (Hu Yajie)]

Page C114, line 24
The token `of' should be in roman font.

Page 237, answer 8.4
The token `or' should be in roman font, to match roman-font `and' and `or'
elsewhere in the book (e.g. page 170).

Pages C242--243, answer 13.8
The token `of' should be in roman font (four times).

Page C267, lines 8 and 15
The `superellipse' and `interpath' should probably be in text italic.