allow teach_trick to use instance variable

define despace for String class to allow for multi line string
use $stderr to allow testing of method_missing
teach count trick to demonstrate sleep method
prefer ternary operator
heavily refactor

locations do not have to be validated
check_yourself removes a hit target from locations
privatized all methods except check_yourself
use a logic hash to determine output
use double bang (!!) to have Array.delete return a boolean
add 'changes since' feedback in report

refactor file variable assignment