Drags, Sliders: Removed power features. Old entry points will pass-through if power=1.0f, otherwise assert + safe fallback. Remove 3 redirection functions (#3361, #1823, #1316, #642)

imgui.cpp

@@ -372,6 +372,14 @@ CODE
  When you are not sure about a old symbol or function name, try using the Search/Find function of your IDE to look for comments or references in all imgui files.
  You can read releases logs https://github.com/ocornut/imgui/releases for more details.
 
+ - 2020/08/17 (1.78) - obsoleted use of the trailing 'float power=1.0f' parameter for DragFloat(), DragFloat2(), DragFloat3(), DragFloat4(), DragFloatRange2(), DragScalar(), DragScalarN(), SliderFloat(), SliderFloat2(), SliderFloat3(), SliderFloat4(), SliderScalar(), SliderScalarN(), VSliderFloat() and VSliderScalar().
+                       replaced the 'float power=1.0f' argument with integer-based flags defaulting to 0 (as with all our flags).
+                       worked out a backward-compatibility scheme so hopefully most C++ codebase should not be affected. in short, when calling those functions:
+                       - if you omitted the 'power' parameter (likely!), you are not affected.
+                       - if you set the 'power' parameter to 1.0f (same as previous default value): 1/ your compiler may warn on float>int conversion, 2/ everything else will work. 3/ you can replace the 1.0f value with 0 to fix the warning, and be technically correct.
+                       - if you set the 'power' parameter to >1.0f (to enable non-linear editing): 1/ your compiler may warn on float>int conversion, 2/ code will assert at runtime, 3/ in case asserts are disabled, the code will not crash and enable the _Logarithmic flag. 4/ you can replace the >1.0f value with ImGuiDragFlags_Logarithmic or ImGuiSliderFlags_Logarithmic flag to fix the warning/assert and get a _similar_ effect as previous uses of power >1.0f.
+                       see https://github.com/ocornut/imgui/issues/3361 for all details.
+                       kept inline redirection functions (will obsolete) apart for: DragFloatRange2(), VSliderFloat(), VSliderScalar(). For those three the 'float power=1.0f' version were removed directly as they were most unlikely ever used.
  - 2020/06/23 (1.77) - removed BeginPopupContextWindow(const char*, int mouse_button, bool also_over_items) in favor of BeginPopupContextWindow(const char*, ImGuiPopupFlags flags) with ImGuiPopupFlags_NoOverItems.
  - 2020/06/15 (1.77) - renamed OpenPopupOnItemClick() to OpenPopupContextItem(). Kept inline redirection function (will obsolete).
  - 2020/06/15 (1.77) - removed CalcItemRectClosestPoint() entry point which was made obsolete and asserting in December 2017.