Internals: Tidying up internal helpers. Fixed a case ImParseFormatTrimDecorations() can return an off by one (out of bound) pointer if the format string is invalid. Extracted ImParseFormatFindEnd() out of TrimDecorations so we can use it to find the format type and replace the %f in old Int apis.

Internals: Fixed DragInt* default format string. InputScalar(), InputScalarN(), removed InputFloatN(), InputInt(). Note that DragInt2/3/4 will %f format strings will currently be broken. (#320, #643, #708, #1011)

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).