Combine reference numbers for grid points starting on buys and sells

[dscotese]

The set command lists all existing reference numbers along with how much was bought and how much was sold and the resulting profit. The problem is that sometimes, for whatever reason, the trade that started as a sell (ref# 2NN[highPrice]) gets replaced as the buy at the lower price (ref# 1NN[lowPrice]).

The fix is to have set recognize that an executed sell at price P matches any executed buy at the next price down, and to therefore list them all together. This only means including both ref#s in each line that set puts out. It would be nice if it also translated the second two digits (which identify the crypto) into the symbol of the crypto. Assuming this is possible, set's output would look like this:

SYMBOL: BuyPrice1 - SellPrice1, bought BBB and sold SSS for PPP
SYMBOL: BuyPrice2 - SellPrice2, bought BBB and sold SSS for PPP
SYMBOL: BuyPrice3 - SellPrice3, bought BBB and sold SSS for PPP

[dscotese]

With the refactor #30 , there is no longer a limited set of pairs, and user reference numbers now use three digits to identify the pair, not two. The feature request is still valid but not yet important to me.