Examples: Simplified mouse wheel handling. (#1463)

Examples: Allegro, Apple, DirectX9/10/11, Glfw+Vulkan :Added support for horizontal mouse wheel. (#1463)

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

Examples: Comments about invalid mouse pos.

Examples: Added a bunch of comments/referencs related to io.WantCaptureMouse, io.WantCaptureKeyboard (#1262, #1237, #1219, #635, #1058, #1051, #912, #533, #703, #446, #459, #364, #213, #52, and more)

IO: io.MousePos needs to be set to ImVec2(-FLT_MAX,-FLT_MAX) when mouse is unavailable/missing. Previously ImVec2(-1,-1) was enough but we'll now accept negative mouse coordinates.

Examples: Vulkan: Fixed an extra validation (tested on Windows with VulkanSDK 1.0.46.0) (#1042)

Merge branch 'vk_small_fix' of https://github.com/martty/imgui into martty-vk_small_fix

Clip negative scissor offsets to zero

Set required depth member for buffer image copy

Fix scissor offset being negative

Fix new Vulkan validation warnings

Vulkan example: Fix validation layer warnings and errors and redeclare gl_PerVertex.

Examples: Vulkan: Shallow stylistic changes (following #879)

Add location decorators & change to use structs as in/out in glsl, update embedded spv (produced with glslangValidator -x)

Null the released resources

Added a void* user_data parameter to Clipboard function handlers. (#875)

Examples: Accessing ImVector fields directly, feel less stl-ey and fix renderer side assert when render list only contains a callback (#810)

Fix Vulkan example for use when a depth buffer is active.

tabs to space, remove braces

maxImageCount may be 0; add missing sType; change to 1 push constant range

Examples: Vulkan: Coding style tweaks.

Vulkan Example: Some code layout changes.

Vulkan Example: Fix synchronization.

Vulkan example.