Removed qApp->processEvents call in MapReader.

Maps are loaded in threads now.
Fix crash when a building has tile layers not in TMXConfig.txt.

The user might add tile layers to TMXConfig.txt, then paint some tiles in
those layers in BuildingEd.  Creating a BuildingMap from that building would
crash if TMXConfig.txt did not have those layers.

I need to display a warning when a .tbx files has tile layers not in TMXConfig.txt.
Only run BMP blending code on parts of the a being displayed.

The blending code used to run on an entire map when one was loaded, which
was noticibly slow.  Now the blending code is run only on the parts of the
map being displayed at any given time.
Fixed hang waiting for a map to load.

If a map was loaded asynchronously but processing was deferred, and the same
was was later loaded non-asynchronously, loadMap() would wait forever.
TileZed reads WorldEd project for to determine adjacent maps.

A single WorldEd project file may be specified in the preferences dialog.
When loading a map to edit, the project file is checked to see if the map
is a cell's map.  If so, that information is used to determine which maps
are adjacent.
ZLotManager loads maps asynchronously.
Removed some unused code.
Fixed g++ compiler warning.
Merge branch 'zomboid' into worlded-lots
ZLotManager loads WorldEd lots.
Added WorldEdDock for displaying the list of lots in a cell.

When a map being edited corresponds to a cell's map in a WorldEd project,
any lots which are diplayed via ZLotManager are listed in the new "WorldEd"
titled dock.  The lots are organized into levels.  Both levels and lots may
individually be shown/hidden.
WorldEdMgr reloads a WorldEd project when it changes on disk.

If the user saved a world in WorldEd, TileZed will redisplay the lots in
any displayed cell-maps.
Fixed invalid index in MapReaderWorker::possiblyRaisePriority().

Hit an assert when the job at the end of the list changed priority.
Forgot to initialize WorldCellLot::mVisible.
Fixed BmpBlender treating exclude2 layer names as possible tile names.
BmpBlender emits layersRecreated() in recreate().

This used to happen when update() was called, but that doesn't happen until
flush() gets called.
Redraw the first level when BMP aliases/rules/blends change.

This used to happen when BmpBlender::update() was called, but that doesn't
happen now until flush() is called.
Added "restart to see changes" to label above worlded file in preferences.
MiniMap displays WorldEd lots.
Fixed MapComposite::mapAboutToChange() clearing layergroups it shouldn't.