Data types: DragScalar, InputScalar: default parameters. Added IM_STATIC_ASSERT(). Comments.

Documentation tweaks, comments

Merge branch 'data_types' ...

# Conflicts:
#	CHANGELOG.txt
#	imgui.cpp

Scrolling: Fixed a case where using SetScrollHere(1.0f) at the bottom of a window on the same frame the window height has been growing would have the scroll clamped using the previous height. (#1804)

Combo: Horizontally offset items using WindowPadding instead of Indent, for consistency.

Internals: Made ContentsRegionRect absolute to reduce confusion. Renamed InnerRect to InnerMainRect, renamed WindowRectClipper to OuterRectClipped.

Internals: Nav: Extracted code into a NavClampToVisibleAreaForMoveDir() + fix debug code + inline some functions, removed obsolete EndChild() comment.

Data types: Fix format srtings with leading blanks. Fix ColorEdit4() to not use obsolete formats (when using IMGUI_DISABLE_OBSOLETE_FUNCTIONS) (#643)

Apply fix from data_types branch, some widgets broken when format string doesn't contains a %. Broken by 92f0165. Data_types branch fix c5fb929.

Internals: Declaring DragBehavior, SliderBehavior in there (no warantee given) as they may be useful to custom widgets.

Data types: Fixed empty format string (or no % specifier) breaking the parsing back of values.

Fix to allow compiling in unity builds where stb_rectpack/stb_truetype may be already included in the same compilation unit.

Settings: Added LoadIniSettingsFromDisk(), LoadIniSettingsFromMemory(), SaveIniSettingsToDisk(), SaveIniSettingsToMemory(), io.WantSaveIniSettings. (#923, #993)

Internals: Removed unnecessary allocation indirection for g.LogClipboard (this only made sense when there was a global context instance)

SliderScalar, VSliderScalar(): Support for any data types. Tested with various ranges/limits. Note that Drag/Slider/Input currently fail if the format string doesn't preview the actual value. Will fix next. (#320, #643, #708, #1011)

Internals: A few selected math helpers are now using template to handle all supported types. Added ImPow() to wrap float/double in a standard manner without calling pow(double) when not needed in Drag code.

Internals: Data types: Made format string optional. DragBehavior: Moved a bit of code outside of the template. Slider tidying up. Removed unnecessary call to fabsf().

DragFloat, DragInt: Default format string is none is passed to the function. Fixed demo using old style %.0f.

Internals: Missing const, some renaming. Tweak legacy fast path.

DragInt, DragScalar: Actually made the fast-past handle the now-most-common case..

DragInt: Patch old format strings to replace %f by %d when using the DragInt() entry point. (#320, #643, #708, #1011)

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