Document action applicability/availability

[drallensmith]

While looking at the available actions vs some of the low-level feature states (validity and others), I realized that I was frequently uncertain about exactly when and by which players various actions were applicable/allowed. (Looking over the code of both HFO and librcsc have helped, but by no means completely.) I have set up a branch in my fork in which I have modified the manual to include the beginnings of a chart/table, found after the actions, giving some of this information. It has rather a large number of '?' entries, however, and an even larger number of 'Y?' or 'N?'; assistance filling it in would be very helpful.

-Allen

P.S. Some other manual improvements - python requirements, cmake setup, etc - are in my master branch; I'll do a PR for them.