v1.16

• General fixing of Columns API to allow filling a cell with multiple widgets before switching to the next column.
• Added documentation INDEX to top of imgui.cpp.
• Fixed unaligned memory access for Emscripten compatibility.
• Various pedantic warning fixes (now testing with Clang).
• Added extra asserts to catch incorrect usage.
• PushStyleColor() / PushStyleVar() can be used outside the scope of a window (namely to change variables that are used within the Begin() call).
• PushTextWrapPos() defaults to 0.0 (right-end of current drawing region).
• Fixed compatibility with std::vector if user decide to #define ImVector.
• MouseWheel input is now normalized.
• Added IMGUI_OVERRIDE_DRAWVERT_STRUCT_LAYOUT compile-time option to redefine the vertex layout.
• Style editor: colors listed inside a scrolling region.
• Examples: tweaks and fixes.