Port gdi04c to New Lua
self-document and un-hardcode the prone sequence prefix
remove unused duplicate stand sequences
remove bogus tab
fix infantry without idle anim staying in fire animation state

closes #5884
add missing TakeCover trait
replace bogus tab with space
Port nod03a to New Lua
Fix a typo in gdi02
Port nod03b to New Lua
Improves tab completion in chat.

Pressing tab after completion now cycles to the next candidate.
Merge pull request #6347 from mizipzor/tab-completion

Improves tab completion in chat.
Adds InaccuracyModifier.
Improve accuracy on level-up.
Moved SellSounds from Building to Sellable & added upgrade to rules.
Merge pull request #6344 from reaperrr/accuracy-modifier

Added InaccuracyModifier
Merge pull request #6362 from atlimit8/SellingSounds

Moved SellSounds from Building to Sellable & added upgrade to rules
remove reference to non-existing idle sequences
Complete ArmorModifier->DamageModifier rename

PR #6303 neglected to rename the "armor" upgrade to "damage" in all
necessary places, as mentioned in
https://github.com/OpenRA/OpenRA/pull/6303#issuecomment-53312209
Merge pull request #6331 from Mailaender/infantry-noidle-fix

Fixed Dune 2000 infantry not showing the waiting animation when ordered to stop firing