refactored tga code to allows use outside of EditorFactories.cpp
added support for grayscale jpeg
fix memory leak in jpeg code
changes in AssetTools to allow to specify precise factory when multiple factories support the same filetype
changes in Plugin.cs to allow binary only plugins
exposed parts of engine API to other modules
[CL 2108453 by Matt Kuhlenschmidt in Main branch]
Please note that file comments had no purpose in nearly all cases and just added visual clutter. The two files that had meaningful file comments had their comments moved into the corresponding classes. There are still hundreds of file comments left in other files that will be removed over time.
Also cleaned up some random stuff along the way:
- relative paths to public headers within the same module are no longer necessary (automatically discovered by UBT now)
- header guards are deprecated, use #pragma once instead (all compilers support it now)
- space between multiple template brackets is no longer required (all compilers support >> now)
- NULL to nullptr, OVERRIDE to override
- spelling errors, whitespace, line breaks
[CL 2104067 by Max Preussner in Main branch]
