Fix another shroud/selection bug in observer mode

In a player view, enemy units would not be unselected when they entered
the shroud.
Merge pull request #6423 from TWaalen/upstream/fix-spelling-luadocs

LuaDocs/Desc attributes spelling fixes
Fixes that only turrets of exiting units are drawn on top of landing craft.
Merge pull request #6428 from reaperrr/landing-craft-fix

Closes #6419
Merge pull request #6388 from DeadlySurprise/bleed

Closes #6198
Replace the empty defaults caused by a null default with nil
Merge pull request #6432 from TWaalen/upstream/luadocs-null-placeholder

Fixes #6078
Replace pre-placed Nod units with reinforcements
Merge pull request #6425 from obrakmann/mission-polish

Mission follow-up
Destroy a paradropped crate if it lands on something that can’t collect it. Fixes #5953, #6427.
Unify the code style across crate actions.
Clean up DuplicateUnitCrateAction.
Add a symlink to libgdiplus in the OS X package.  Closes #6413.
Merge pull request #6426 from obrakmann/fix6421

Fix a number or bugs wrt shroud/selection interaction in observer mode
Merge pull request #6418 from Mailaender/d2k-idle-stand

Cleaned up Dune 2000 infantry sequences
Update the current developers in AUTHORS.
Adds ability to paste text (ctrl/cmd+v) into chat.
Merge pull request #6438 from pchote/avoid-3point8-fail

Add a symlink to libgdiplus in the OS X package.
Merge pull request #6440 from pchote/authors

Update the current developers in AUTHORS.
Disable replay saving for campaign missions.