Force-Field

Bug Fixes.

- Fixed bug where player could walk through the force-field backwards

- Fixed bug where player could remove the force-field with a right click.

- Fixed bug where, if a player managed to get inside the forcefield block, they would be able to move freely.

- Fixed bug where player could get through the force-field if they were sneaking.

- Set option to disable flight if a player hits the force-field.

Player can still get through the force-field if they have greater than speed 3. (You can fix this by making the force-field 2-3 blocks thick.)