DragFloat, SliderFloat: Rounding scalar using the provided format string instead of parsed precision. (#648)

DragFloat/SliderFloat internal InputScalar trip trailing decoration off the format string when presenting an edit box to the user. (#648)

DragFloat/SliderFloat internal InputScalar relies on the user supplied format string to format and parse value. (#648) ...

The trailing text after the format will be displayed in the InputText but not affect back parsing. Ideally we can try to strip it later.

DragDrop: Removed const qualifier from ImGuiPayload 's void* data, easing casting on user side.

InputFloat,InputFloat2,InputFloat3,InputFloat4: Added variations taking a more flexible and consistent optional "const char* format" parameter instead of "int decimal_precision". This allow using custom formats to display values in scientific notation, and is generally more consistent with other API. Obsoleted functions using the optional "int decimal_precision" parameter. (#648)

Renamed all "display_format" arguments to "format" to emphasis that they also affect rounding of values. (#648, #642)

SliderFloat, DragFloat: Fix to allow input of scientific notation when Ctrl+Clicking a slider or drag, matching the change done in c19b2781 for InputFloat(). (#648, #1011)

DragFloat, DragInt: Cancel mouse tweak when current value is initially past the min/max boundaries and mouse is pushing in the same direction (keyboard/gamepad version already did this).

Internals: DragBehavior: tweaks internals.

Internals: Reordered parameters of DataTypeFormatString() internal helper functions and shallow tweaks.

InputText: Fixed returning true when edition is cancelled with Esc and the current buffer matches the initial value.

Viewport: Exposing SetNextWindowViewport(). Used in demo and old/obsolete SetNextWindowPosCenter() (which is an interesting case). Fixed back-end likely crash calling GetFocus() after viewport destruction. Fixed metrics crash.

Viewport, Platform: Refresh monitor list (win32, glfw) + avoid calling GetWindowFocus before platform window creation to not require of backend to null-check things inconsistently. (#1542)

Viewport: Removed unnecessary fields (now that the coordinate system is consistent accross viewports): MouseRefPrevViewport, MouseClickedPosViewportId. (#1542)

Viewport, Platform: Using Platform_GetWindowFocus to provide a much stronger heuristic of platform z-order, in replacement for when the back-end cannot provide io.MouseHoveredViewport. The pressure for it to work well increased with the use of viewports by popups/menus. (#1542)

Fixed static analyzers warnings with bool literals (#1775) ...

* Use `false` instead of `0` for a bool literal.
* Simplify calls to RadioButton to not need bool literals.

Viewport: Moved ScaleWindow* code in a proper location. Various comments.

Added IMGUI_CHECKVERSION() macro to compare version string and data structure sizes in order to catch issues with mismatching compilation unit settings. (#1695, #1769)

Misc: tweaks + minor changes merged from master to reduce branch drift. Removed code that ended up unused.

Merge branch 'master' into viewport ...

# Conflicts:
#	imgui.cpp
#	imgui.h
#	imgui_internal.h

Misc: Stop moving window if mouse position becomes invalid. Flagged menus are _NoMove for sanity.

Misc: NavCalcPreferredRefPos selects between mouse and nav reference position + added sanity assert (merged from viewport branch to minimize branch drift).

Begin: Shuffled some code, _should_ have no side-effect. Clear NextWindowData in one call and more consistently. (merged from viewport branch to minimize branch drift).

Misc: Comments and shallow/small changes (merged from viewport branch to minimize branch drift).

ImGuiTextBuffer::appendfv needs to va_end the args_copy.

Viewport: Avoid creating viewport on drag (fix cc882b0)

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/allegro5_example/imgui_impl_a5.cpp
#	examples/allegro5_example/imgui_impl_a5.h
#	examples/allegro5_example/imgui_impl_allegro5.cpp
#	examples/allegro5_example/imgui_impl_allegro5.h
#	examples/allegro5_example/main.cpp
#	examples/imgui_impl_allegro5.cpp
#	examples/imgui_impl_allegro5.h
#	imgui.cpp
#	imgui_internal.h

Internals: Removed unecessary Pos/PosFloat separation, only reason appears to be mostly pre-1.0. The only piece of code that I expected sub-pixel window position to matter actually already round its delta (wrongly so, will fix later/separately if we want).

Viewport: Tidying up AddUpdateViewport() calls. Moved flags argument. Removed extraneous mid-frame call to FindPlatformMonitorFromRect(). (#1542)

Viewport: Fixed glitches with newly appearing menus creating viewport while the underlying imgui window should be hidden. (#1542)