Updated warning message to specify folder that will be cleaned.

Signed-off-by: Dalton Pelc <daltonjpelc@gmail.com>
Updated for the newer icon/logo in the launcher. Also updated for the newer Minecraft assets URL, and fixed some missing folder issues in certain cases causing crashes

Signed-off-by: Dalton Pelc <daltonjpelc@gmail.com>
Merge branch 'master' of https://github.com/TechnicPack/TechnicLauncher