Fix mission accomplished notifications and video playback
make gdi04c a bit easier
remove fake idle animations
add missing grenadier idle animation
remove duplicate bazooka stand sequences
Fix selection glitch in observer mode

Fixes #6421.
Reset selection when switching player shroud in observer mode

The selection will be reset when switching from any shroud view to a
player shroud view. The selection will be kept when switching from any
view to either 'All players' or 'Shroud disabled' view.
Fix another shroud/selection bug in observer mode

In a player view, enemy units would not be unselected when they entered
the shroud.
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.