Minor API comments and tweaks, standardize index used in imgui.h. Tables: tweaked TableSetupColumn() assert to use IM_ASSERT_USER_ERROR().

Author: ocornut

docs/CHANGELOG.txt

@@ -132,6 +132,8 @@ Other Changes:
  VERSION 1.79 (Released 2020-10-08)
 -----------------------------------------------------------------------
 
+Decorated log: https://github.com/ocornut/imgui/releases/tag/v1.79
+
 Breaking Changes:
 
 - Fonts: Removed ImFont::DisplayOffset in favor of ImFontConfig::GlyphOffset. DisplayOffset was applied
@@ -224,6 +226,8 @@ Other Changes:
  VERSION 1.78 (Released 2020-08-18)
 -----------------------------------------------------------------------
 
+Decorated log: https://github.com/ocornut/imgui/releases/tag/v1.78
+
 Breaking Changes:
 
 - Obsoleted use of the trailing 'float power=1.0f' parameter for those functions: [@Shironekoben, @ocornut]

imgui.cpp

@@ -124,7 +124,7 @@ CODE
    - You can apply arithmetic operators +,*,/ on numerical values. Use +- to subtract (because - would set a negative value!)
    - Controls are automatically adjusted for OSX to match standard OSX text editing operations.
  - General Keyboard controls: enable with ImGuiConfigFlags_NavEnableKeyboard.
- - General Gamepad controls: enable with ImGuiConfigFlags_NavEnableGamepad. See suggested mappings in imgui.h ImGuiNavInput_ + download PNG/PSD at http://goo.gl/9LgVZW
+ - General Gamepad controls: enable with ImGuiConfigFlags_NavEnableGamepad. See suggested mappings in imgui.h ImGuiNavInput_ + download PNG/PSD at http://dearimgui.org/controls_sheets
 
 
  PROGRAMMER GUIDE
@@ -156,18 +156,20 @@ CODE
  HOW TO UPDATE TO A NEWER VERSION OF DEAR IMGUI
  ----------------------------------------------
  - Overwrite all the sources files except for imconfig.h (if you have made modification to your copy of imconfig.h)
- - Or maintain your own branch where you have imconfig.h modified.
+ - Or maintain your own branch where you have imconfig.h modified as a top-most commit which you can regularly rebase over master.
+ - You can also use '#define IMGUI_USER_CONFIG "my_config_file.h" to redirect configuration to your own file.
  - Read the "API BREAKING CHANGES" section (below). This is where we list occasional API breaking changes.
    If a function/type has been renamed / or marked obsolete, try to fix the name in your code before it is permanently removed
    from the public API. If you have a problem with a missing function/symbols, search for its name in the code, there will
    likely be a comment about it. Please report any issue to the GitHub page!
- - Try to keep your copy of dear imgui reasonably up to date.
+ - To find out usage of old API, you can add '#define IMGUI_DISABLE_OBSOLETE_FUNCTIONS' in your configuration file.
+ - Try to keep your copy of Dear ImGui reasonably up to date.
 
 
  GETTING STARTED WITH INTEGRATING DEAR IMGUI IN YOUR CODE/ENGINE
  ---------------------------------------------------------------
  - Run and study the examples and demo in imgui_demo.cpp to get acquainted with the library.
- - In the majority of cases you should be able to use unmodified backends files available in the examples/ folder.
+ - In the majority of cases you should be able to use unmodified backends files available in the backends/ folder.
  - Add the Dear ImGui source files + selected backend source files to your projects or using your preferred build system.
    It is recommended you build and statically link the .cpp files as part of your project and NOT as shared library (DLL).
  - You can later customize the imconfig.h file to tweak some compile-time behavior, such as integrating Dear ImGui types with your own maths types.
@@ -348,7 +350,7 @@ CODE
          0.0f= not held. 1.0f= fully held. Pass intermediate 0.0f..1.0f values for analog triggers/sticks.
     - We uses a simple >0.0f test for activation testing, and won't attempt to test for a dead-zone.
       Your code will probably need to transform your raw inputs (such as e.g. remapping your 0.2..0.9 raw input range to 0.0..1.0 imgui range, etc.).
-    - You can download PNG/PSD files depicting the gamepad controls for common controllers at: http://goo.gl/9LgVZW.
+    - You can download PNG/PSD files depicting the gamepad controls for common controllers at: http://dearimgui.org/controls_sheets
     - If you need to share inputs between your game and the imgui parts, the easiest approach is to go all-or-nothing, with a buttons combo
       to toggle the target. Please reach out if you think the game vs navigation input sharing could be improved.
  - Mouse: