Added -chunkinstalldirectory and -chunkinstallversion to UAT commandline options.
Added Chunk Dependency Graph for use with -manifests.
HTTPChunkInstaller correctly re-uses old builds to reduce download sizes.
ChunkInstaller delegates correctly use delegate handles.
Windows uses HTTPChunkInstaller by default if enabled in project Build.cs.
Switched HTTPChunkInstaller tasks to threads.
[CL 2499607 by James Moran in Main branch]
Only a simple pointer to UObjects can be a parameter of BlueprintCallable (or BlueprintImplementableEvent.. etc) function. No WeakObjPtr or AssetSubclassOf is accepted. Strict check in UHT.
#codereview Steve.Robb, Richard.Hinckley
[CL 2499396 by Maciej Mroz in Main branch]
I have reviewed each change carefully, but it is a large change and I could have missed something! Here is a summary of the types of changes in this CL:
* Made nullptr checks consistent (the plurality of the changes are of this type)
* Completed switch statements (IE, switch did not explicitly handle default case, but had unhandled enum entries - this is the second most popular type of fix)
* Removed unused variables
* Removed redundant initializations
* WidgetNavigationCustomization.cpp was fixed by the owner
* integers converted to floats where result was stored in a float
* Removed redundent null checks (e.g. before delete statements)
* Renamed variables to prevent non-obvious shadowing
* Fixed use of bitwise & when checking for equality to an enum entry (which is often 0)
* Fixes for some copy paste errors (e.g. FoliageEdMode.cpp)
[CL 2498053 by Dan Oconnor in Main branch]
* Filters were not earlying out of recursive directory searches in cases where a directory partially matched a file specification.
* Trailing file wildcards would match against directory names, so -/Something* would exclude /Something/...
* Path specifications starting with ... would have an additional ... token appended.
[CL 2497897 by Ben Marsh in Main branch]
