Version 1.66b (will revisit how to change IMGUI_VERSION_NUM across ve…

…rsions, this commit reduces the numerical IMGUI_VERSION_NUM compared to the commit on Nov 22).

Version 1.66

Version 1.65

Fix missing include on some systems to use intptr_t. (ocornut#2036, o…

…cornut#2054)

Changelog tweaks/typos

Version 1.61 + todo additions

Version 1.60 (missed the string). Will retag.

Version 1.53

Version 1.52