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

Ran a spell checker for sanity.

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)

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

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)

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)

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).

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

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

Merge branch 'master' into viewport ...

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

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

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

Fix various typos.

Internals: Removed misleading ImRect::FixInverted + fix minor formatting in Readme. ...

Demo: Fixed Overlay: Added a context menu item to enable freely moving the window.

Window: Relaxed the internal stack size checker to allow Push/Begin/Pop/.../End patterns to be used with PushStyleColor, PushStyleVar, PushFont without causing a false positive assert. (#1767)

InputText: On Mac OS X, support Cmd+Shift+Z for Redo. Cmd+Y is also supported as major apps seems to default to support both. (#1765)

Columns: Fixed a bug introduced in 1.51 where columns would affect the contents size of their container, often creating feedback loops when ImGuiWindowFlags_AlwaysAutoResize was used. (#1760)

Window: Fixed windows using the ImGuiWindowFlags_NoSavedSettings flag from not using the same default position as other windows. (#1760)

InputText: Tweak to make the if statement more readable + update Changelog (#1747)

Examples: Allegro 5: Renamed bindings from imgui_impl_a5.cpp to imgui_impl_allegro5.cpp.

Examples: Allegro 5: Added support for 32-bit indices setup via defining ImDrawIdx, to avoid an unecessary conversion (Allegro 5 doesn't support 16-bit indices).

Merge branch 'master' into viewport ...

# Conflicts:
#	examples/imgui_impl_dx10.cpp
#	examples/imgui_impl_dx11.cpp
#	examples/imgui_impl_dx12.cpp
#	examples/imgui_impl_dx9.cpp
#	examples/opengl2_example/imgui_impl_glfw_gl2.cpp
#	examples/opengl3_example/imgui_impl_glfw_gl3.cpp
#	examples/sdl_opengl2_example/imgui_impl_sdl_gl2.cpp
#	examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp
#	examples/vulkan_example/imgui_impl_glfw_vulkan.cpp
#	imgui.cpp
#	imgui_internal.h

Fixed DisplaySafeAreaPadding not affecting popups/tooltips/menus at it should have (partly broken in 2e5577f).

BeginMainMenuBar: Followup to 1e41bad9. Removed public window flag. DisplaySafeAreaPadding defaults to (3,3) instead of (4.4). Comments, tab to spaces, Changelog. (#1439)

Fixed default proportional item width lagging by one frame on resize + miscellaneous minor tweaks.

Fix typos KeyDown => KeysDown