Fix for timing inventory changed events

Sending them after saving the component causes the ownership of the item
to be changed for when the event is handled.
Fixed support for escape to close ui screen layers - now correctly iterates the layer stack.
Reworked ColumnLayout into a RowLayout
Merge pull request #953 from mkienenb/PR-MultiRowLayout

Reworked ColumnLayout into a RowLayout
Fix for mouse wheel going through modal windows.
Renamed pause menu to ingame menu.
Merge branch 'develop' of git@github.com:MovingBlocks/Terasology.git into develop
Flip pickup/drop individial stack items with mouse wheel.
Merge #952 from @Josharias - inventory timing tweak
Add WorldAtlas to API so LightAndShadow won't crash on world create
Doc updates for stable build. New included modules: CakeLie, CopperAndBronze, Journal, Minimap, MultiBlock, Workstation, Zones