Internal: DragScalar(), InputScalar() now support signed/unsigned, 32/64 bits, float/double data types. (#320, #643, #708, #1011)

Internals: DragFloat: Fixed power handling. Use an temporary accumulator and no absolute values so we will be able to manipulate double as well as 64-bit integers. (#1011, #708, #320)

Internals: DragFloat: Removed DragSpeedScaleFast/DragSpeedScaleSlow since it's not yet usable and Nav version doesn't have an equivalent.

Internals: Data types: Added s64, u64 data types. Added support in InputScalar(). Removed internal.h InputScalarEx() to InputScalar(). Removed cheap-relative-operators support in recently added U32 data path, since this is heading toward being legacy code. + Fixed InputDouble parsing code. (#1011, #320, #708)

Comments about using "power curves". Demo tweaks. (#648)

SliderFloat: Fixed grab size and steps with %g format. (#642, #1301)

DragFloat/SliderFloat internal InputScalar trim leading/trailing spaces emitted from the format string when presenting an edit box to the user. (#648) ...

Follow up to 6881d06

Internals: Renamed IsCharIsSpace() to IsCharIsBlank*() to match standard terminlogy and added ascii/u16 variations.

Internals: InputScalarEx: Tweak internals so there is a fast path for the simple case. ...

(in particular because it makes it clear what the extra code is for, so people tempted to create their own InputText data transform/handler understand how little is actually needed)

Internals: Added ImGuiDataType_Uint32 data type which is usable with InputScalarEx().

Nav: Fixed hovering a Selectable() with the mouse so that it update the navigation cursor. Fixed c8b9b2c6 which was incorrect (#787)

Internals: Tweaked ParseFormatPrecision(), clarified its more limited purpose, allowing 2-digits precisions since it makes (some) sense for doubles. (#648)

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.

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.

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: 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.