Removed un-needed header.
Removed free-run mode.

- It was causing outrageous memory leaks and heavy processor
  utilization. I'm not exactly sure why, since the only difference is
  the lack of thread sleeping, but there's no real reason for it anyway.

- The default execution speed is now a frequency of 10 MHz.
Merge branch 'dev' of github.com:hakuch/Dcpu16Universe into dev