Merge branch 'master' into context

ImVec2: added [] operator. This is becoming desirable for some types of code, better added sooner than later.

Style Added style.MouseCursorScale, may remove (#939).

Merge branch 'master' into context

Comments

Added IMGUI_USER_CONFIG to define a custom configuration filename. (#255, #1573, #1144, #41)

ImVector comment (#1577)

Merge branch 'master' into context

Comments (#1567)

Added SetNextWindowBgAlpha() helper. (#1567) particularly helpul with the marking of the old 5-parameters version of Begin() as obsolete.

Comments + added legacy renamed GetItemsLineHeightWithSpacing() as stated in the doc, fixes 6190ab0

Style: Exposed ImGuiStyleVar_WindowTitleAlign, ImGuiStyleVar_ScrollbarSize, ImGuiStyleVar_ScrollbarRounding, ImGuiStyleVar_GrabRounding + added an assert to reduce accidental breakage. (#1181)

Reorganized context handling to be more explicit, ...

- YOU NOW NEED TO CALL ImGui::CreateContext() AT THE BEGINNING OF YOUR APP, AND CALL ImGui::DestroyContext() AT THE END.
- removed Shutdown() function, as DestroyContext() serve this purpose.
- you may pass a ImFontAtlas* pointer to CreateContext() to share a font atlas between contexts. Otherwhise CreateContext() will create its own font atlas instance.
- removed allocator parameters from CreateContext(), they are now setup with SetAllocatorFunctions(), and shared by all contexts.
- removed the default global context and font atlas instance, which were confusing for users of DLL reloading and users of multiple contexts
(#1565, #586, #992, #1007, #1558)

Context: Renamed SetMemoryAllocators() to SetAllocatorFunctions(). Tweaked comments. (#1565, #586, #992, #1007, #1558)

Context: Removed allocator parameters from CreateContext(), they are now setup with SetMemoryAllocators() and shared by all contexts. (#1565, #586, #992, #1007, #1558)

ImFontAtlas: Added TexUvScale (= 1.0f / (float)TexWidth, 1.0f / (float)TexHeight)

ImFontAtlas: Moved mouse cursor data out of ImGuiContext, fix drawing them with multiple context. Also remove the last remaining undesirable dependency on GImGui in imgui_draw.cpp, finishing the work recently done with ImDrawListSharedData. Hurra! (#939)

Horizontal mouse wheel: renamed io.MouseHorizWheel to io.MouseWheelH. Reorganized the code in NewFrame(). Examples: Updated GLFW+GL and SDL+GL accordingly. (#1463)

Merge branch 'tseeker/20171127-feature-horiz-wheel' of https://github.com/tseeker/imgui into tseeker-tseeker/20171127-feature-horiz-wheel ...

# Conflicts:
#	examples/sdl_opengl2_example/imgui_impl_sdl_gl2.cpp
#	examples/sdl_opengl3_example/imgui_impl_sdl_gl3.cpp

Drag and Drop: Fix comment. Removed IMGUI_PAYLOAD_TYPE_DOCKABLE from master branch. (#143)

Drag and Drop: Increased payload type string to 12 characters instead of 8.(#143)

NewFrame(): Added an assert to detect incorrect filling of the io.KeyMap[] array earlier. (#1555) + comments.

Comments about Begin/End pair and handling of return value.

Internal: DrawData: Tidying, renaming.

Made obsolete IsAnyWindowHovered()/IsAnyWindowFocused() static inline. static only tends to trigger warnings. (#1382)

Added ImGuiHoveredFlags_AnyWindow, ImGuiFocusedFlags_AnyWindow. Obsoleted IsAnyWindowHovered()/IsAnyWindowFocused() in favor of IsWindowHovered(ImGuiHoveredFlags_AnyWindow)/IsWindowFocused(ImGuiFocusedFlags_AnyWindow). Added to demo. (#1382)

Added ImGuiKey_Insert for future use. Setup in all example bindings. (#1541)

Popups: Comments, reorganize bits of the header section, renamed parameters.

BeginPopup: Exposed extra_flags publicly. (#1533)

Examples: Using IM_OFFSETOF macro. + Comments