* Moved Slate.h into SlateBasics.h and began shifting less commonly used headers into SlateExtras.h.
* Slate.h now simply includes SlateBasics.h and SlateExtras.h.
* Slate.h includes a deprecated warning now to indicate that SlateBasics.h + specific includes should be used instead.
* Moved dozens of inlined functions using Slate widgets into .cpp files to avoid header dependencies.
* All code samples now include SlateBasics.h and SlateExtras.h so future shifts will not break most those projects, but not trigger the deprecation warning of including Slate.h.
#BUN
[CL 2329610 by Wes Hunt in Main branch]
Handled log listing change broadcast message & selected the correct log.
Also corrected log list to use localized title.
TTP# 347358 - EDITOR: Message log (sometimes?) does not select the correct category
#codereview Max.Preussner
[CL 2306630 by Thomas Sarkanen in Main branch]
- Redesigned the layout of the message log viewer
- Added 'Action' message token type for actionable items
- Started to remove message token delegates in favor of Action tokens
- NULL to nullptr
[CL 2299749 by Max Preussner in Main branch]
- Removed UI for Built-In Stats. Martin didn't like the feature but I've left the code in just in case people miss it.
- Removed useless bar at the bottom of the stats window.
- Hackily canceled some unnessessary compilaton when opening the editor.
[CL 2272297 by Simon Tovey in Main branch]
- Part of PR #306 by amigo and #ue4linux community.
- Mostly things like initialization order changes, but also platform-specific additions/improvements.
#codereview Josh.Adams
[CL 2235441 by Dmitry Rekman in Main branch]
