Drastic fix to prevent passing the border

stop teleport if it would hit the border

Completely cancel the teleport if it would hit the border. This allows the vanilla behavior when encountering the border to always work, and should always prevent players from getting past the border. Will stop the skill, but not use the skill. This only happens if it would hit the border (standing at the border and using a skill not directed at the border will still work).

Fixes #795 Fixes #1011