Update German frontend and Minigun translation

Rope training: Fix confused order of retract/extend controls

Rope Knock Challenge: Remove trailing space of name "doomy "

Death02: Add Delay=600

Update German Lua translation

Use mktemp in update_lua_locale_files.sh

Stop SplitByChar also lowercasing the entire string. Fixes bug #581. It's weird that a function with this name would lowercase the whole string. Nemo and I have checked the history and code for any justifications of the lowercasing but we found none. I have checked in the code if anything actually depends on SplitByChar also lowercasing the string but I found nothing. It would surprise me since it's not obvious from the name IMO is bad coding practice anyway. Bug 581 is fixed by this because cLocale was (incorrectly) lowercased, which broke locale names like pt_BR to pt_br.

Lua: Rename global variable “L” to “LOCALE” Srsly, WTF? If we have to use global variables, at least give them descriptive names.

Sort all core missions in training menu more logically The missions are now sorted as specified in the new order.cfg files in the Missions subfolders. Training missions are now sorted in the order you should play them. Challenges are semi-logically grouped. Scenarios are roughly sorted by difficulty. All missions not mentioned in order.cfg are simply added in no particular order at the end.

Frontend: Lead first-time player to training page on start