adds --ladderversion flag, which runs game on version 4.10

[dysonreturns]

Depends on python-sc2 merge: https://github.com/BurnySc2/python-sc2/pull/213 As discussed, sometime in SC2 version 5.0.x, the map becomes unclickable and you can't issue unit commands.

To allow users to launch on v4.10 (which is the ladder version) this code adds the boolean switch --ladderversion. It brings back the ability to navigate the minimap and issue commands while your bot is busy.

Note, I had to change some imports which were renamed on latest python-sc2. The module kill_switch is now KillSwitch.

Tested against latest python-sc2 at the commit mentioned in the above PR. If that gets merged, this can be merged. Works for bot-vs-ai and bot-vs-bot.