display the last ServerError in the connection failed dialog

closes #2727
fix some plenks

no logic changes
inform the user which sound engine is used
Lobby, Add Bots button
Simplify and increase robustness of Shroud et al. Fixes #3440.
Add an extra sanity check.
Only update vis for actors in the world. Fixes #2726.
Merge pull request #3420 from Mailaender/sound-info

Display the current sound engine in the console
Merge pull request #3441 from Mailaender/display-server-error

Display ServerError in CONNECTIONFAILED_PANEL
Merge pull request #3371 from aperkins81/bleed

Add Bots button in Lobby
Remove harvester dependency on RenderUnit.
Add WithHarvestAnimation for TS and D2K harvester animations.
Allow Harvester to define the number of harvestable facings.
Add D2k harvest animation.

harvest2.shp is movingsand2.shp with a corrected frame order.
Fix D2k harvester dock animation.
Merge pull request #3454 from pchote/cargo-antivis

Fix shroud glitches once and for all
Merge pull request #3458 from pchote/harvester-animations

Fix the harvest animations for TS and D2k.
dead harvester will splatter Tiberium
port harvester documentation to the new inline Desc format
rename ore to the more generic name resources everywhere