Clean killers handling in movepicker

Original patch from Joona with added optimizations
by me.

Great cleanup of MovePicker with speed improvment of 1%

No functional change.

Signed-off-by: Marco Costalba <mcostalba@gmail.com>

src/application.cpp

@@ -47,7 +47,6 @@ Application::Application() {
     init_uci_options();
     Position::init_zobrist();
     Position::init_piece_square_tables();
-    MovePicker::init_phase_table();
     init_eval(1);
     init_bitbases();
     init_threads();