* Update the following projects.

* Add the following projects.

-- Abseil - C++ Common Libraries: https://github.com/abseil/abseil-cpp
-- AngelScript: https://www.angelcode.com/angelscript/
-- CEGUI: http://cegui.org.uk/
-- ChaiScript/ChaiScript: Embedded Scripting Language Designed for C++: https://github.com/ChaiScript/ChaiScript/
-- Chromium Embedded Framework: https://bitbucket.org/chromiumembedded/cef
-- cppunit: https://sourceforge.net/projects/cppunit/
-- Dear ImGui: Bloat-free Immediate Mode Graphical User interface for C++ with minimal dependencies: https://github.com/ocornut/imgui
-- dropbox/json11: A tiny JSON library for C++11: https://github.com/dropbox/json11
-- Duktape: https://duktape.org/
-- Embeddable Common-Lisp: https://common-lisp.net/project/ecl/main.html
-- Google V8: https://v8.dev/
-- google/flatbuffers: Memory Efficient Serialization Library: https://github.com/google/flatbuffers
-- Googletest - Google Testing and Mocking Framework: https://github.com/google/googletest
-- jsoncpp: A C++ library for interacting with JSON: https://github.com/open-source-parsers/jsoncpp
-- Little CMS: http://www.littlecms.com/
-- Microsoft/ChakraCore: ChakraCore is the core part of the Chakra JavaScript engine that powers Microsoft Edge: https://github.com/Microsoft/ChakraCore
-- ReactiveX/RxCpp: Reactive Extensions for C++: https://github.com/ReactiveX/RxCpp
-- Scintilla: https://scintilla.org/
-- SDL: Simple DirectMedia Layer: https://www.libsdl.org/
-- StrTk: http://www.partow.net/programming/strtk/index.html
-- vurtun/nuklear: A single-header ANSI C gui library: https://github.com/vurtun/nuklear