Make sure actors are removed from control groups when captured

Fixes #5976.
Introduce RangeCircleRenderable.
Split selectable rendering into *Renderables.
Add UISpriteRenderable for screen-space decorations.
Change IPostRenderSelection and IPlaceBuildingDecoration to return renderables.
Change IOrderGenerator.RenderAfterWorld to return Renderables.
Added Grenadier as Atreides starting unit
remove .php prefixes related to master server
Merge pull request #6062 from ihptru/masterphp

remove .php prefixes related to master server
AUTHORS
INotifyCreated
Appears to fix sticky locking of preplaced buildings
Allow actors that are not buildings to be sold.

The more humane way to refund units (as opposed the grinding them).
Fixed D2K turrets.
Merge pull request #6065 from atlimit8/SellNonBuildings

Sell non buildings
Merge pull request #6014 from atlimit8/FixBuildingsLockedOnWorldLoad

Fix buildings locked on world load
Merge pull request #6061 from MustaphaTR/d2k-starting-units

Added grenadier as Atreides starting unit
Merge pull request #6040 from pchote/more-renderables

Convert RenderAfterWorld to use Renderables.
Fix mouse event filtering in BackgroundWidget.
Allow ImageWidget to filter mouse events.