now allows arrow key missile targeting after

after first solved missile. Need to add a trigger to use it before the
first missile is solved, but works great! Arrow keys properly loop
through available missiles and hitting enter or return clicks on the
currently selected missile. Now the whole game can be played with the
numpad after the first click!
Merge branch 'master' of https://github.com/Mezuzi/TrinitySenior_cyber_security