Clear gmSwitch before activating switcher
If if you pressed [Switch Hedgehog] key and THEN enabled the
Switch Hedgehog utility, you immediately switch. This was mildly
confusing.
Lua scripts for engine testing. These scripts are the same as other Lua scripts
in Hedgewars, but you ought to call `EndLuaTest(TEST_SUCCESSFUL)` or
`EndLuaTest(TEST_FAILED)` when the test is completed.