show a user friendly description of the starting unit template

closes #6209
Add support for C&C Generals .big archive files
beautify starting unit notification when joining server

move LobbySettingsNotification into it's own ServerTrait
Merge pull request #6255 from ScottNZ/generals

Add support for C&C Generals .big archive files
Suppress map change order when selecting the same map.  Fixes #6206.
Merge pull request #6271 from pchote/map-kick-fix

Avoid sending the map change order when selecting the same map.
Merge pull request #6217 from Mailaender/starting-units-classname

Fixed lobby start unit notifications not showing class names
Introduces ReloadModifier
and renames ROF -> ReloadDelay
ReloadModifier & ROF -> ReloadDelay yaml changes
Upgrade rule for ROF > ReloadDelay renaming.
Added tab completion to in-game chat.

Both player names and chat commands can be completed.
Names of local players and bots are not candidates for completion.
If a completed name is the first word ": " is appended to the end.
The hotkey for toggling team/all chat has been moved to left Alt.
Code cleanup based on code review.

Fixes multiple enumeration of IEnumerable.
Fixes return value of pure method not used.
Converted OnTabKey and OnClick handlers to method groups.
Removed one set of redundant parenthesis.
Replaced explicit type with var.
Added tab completion to lobby chat.

Also fixes accidental reversion of one word logic during cleanup.
Fields that could be readonly are now readonly.
Fixed starport and palace
Adds length display support for PCM & IMA music.
Update AUTHORS

Added myself as requested by Mailaender.
Merge pull request #6089 from reaperrr/wavlength

Add WavSoundLength to show track length in music player
Merge pull request #6079 from reaperrr/rof-modifier

Adds ReloadDelay modifier & renames ROF to ReloadDelay
Fixes year numbers in license text in file headers.
Merge pull request #6296 from mizipzor/fix-license

Fixes year numbers in license text in file headers.