packet_classify packets have pronunciation guides in them

[alopezlago]

The packets used for classification have some extraneous words:

• "10" and "points" appears in all tossups
• Words in pronunciation guides also appear, but these wouldn't be too useful for classification, since pronunciation guides differ per packets

Consider putting "10" and "points" as stop words. Filtering out pronunciation guides is trickier. You may need a parameter that takes in what character is used to denote a pronunciation guide (braces or square brackets).

[geoffrey-wu]

first part of this issue fixed with 572e247