Update and change license information of Droplet sounds, now it's CC BY 3.0
Was previously labelled under license CC Sampling+ 1.0, which is
considered non-free by FSF, OSI and DFSG.
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.