Makes LineBuild logic require building dimensions of 1x1
Added flag to Mobile/AircraftInfo: MoveIntoShroud.
Does not change the audio feedback given.
Fix instant-use and AllowMultiple support powers.

Fixes #2185, #6090.
Merge pull request #6022 from Phrohdoh/MoveToShroud

Locomotion MovesToShroud bool.
Merge pull request #6135 from pchote/support-fix

Fix instant-use and AllowMultiple support powers.
Merge pull request #6069 from atlimit8/LineBuild-1x1Only

Makes LineBuild logic require building dimensions of 1x1
Add support for mission objectives

Objectives can be either primary or secondary objectives. Primary ones
influence the outcome of the game.  If all primary objectives are
completed the game is won, and lost when any of them fails.

Objectives can be added at any stage during the game, allowing to react
dynamically to game events.

The objectives backend only contains the information about the
objectives themselves. It does not check if objectives are completed or
failed.  Instead, the state of objectives must be manually marked. The
backend, however, does check whether the game is won or lost.
Make Conquest- and StrategicVictoryConditions use objectives backend

Note: 3rd party KotH maps will need to be modified to work correctly
with this change.  Previously, StrategicVictoryConditions was a
supplement to ConquestVictoryConditions.  After this change, each works
by itself.  So KotH maps will need to remove the ConquestVictoryConditions
trait from the player definitions, or both victory conditions will have
to be satisfied to win the game.
Move trigger lists into a dictionary for easier access and enumeration
Add mission objectives to Lua interface
Make CheckboxWidget honour GetText()
Copy checkbox markings from TD to the other mods
Add a mission objectives GUI panel
Add end game dialog
Make necessary changes to existing maps