Corrected improper use of cfg["foo"] comparison in unit.cpp

Changed from cfg["foo"] > number, to cfg["foo"].blank() in 2 if statements.
Correct recall_cost assignment and 2 small whitespace fixes

Correctly initialize the recall_cost in unit.cpp by removing unneeded ifs
and a cfg["recall_cost"].to_int() in the constructor.  Two minor white
space fixes to get everything to line up nicely are included.