Renamed ImGuiNavFlags io.NavFlags to ImGuiConfigFlags io.ConfigFlags. (#787)

Examples: NULL pointers for consistency.

Examples: Vulkan: Formatting and tweaks (to match SDL's main).

Examples: Vulkan: Fixed GLFW calls.

Examples: Vulkan: Extracted into imgui_impl_vulkan.*, reused imgui_impl_glfw* files.

Examples: Vulkan: Fix for empty draw data (init time) + fixed warning.

Merge branch 'context' ...

# Conflicts:
#	examples/allegro5_example/main.cpp
#	examples/directx10_example/main.cpp
#	examples/directx11_example/main.cpp
#	examples/directx9_example/main.cpp
#	examples/marmalade_example/main.cpp
#	examples/opengl2_example/main.cpp
#	examples/opengl3_example/main.cpp
#	examples/sdl_opengl2_example/main.cpp
#	examples/sdl_opengl3_example/main.cpp
#	examples/vulkan_example/main.cpp

Nav: Examples: Added commented out io.NavFlags |= ImGuiNavFlags_EnableKeyboard to all examples. (#787)

Merge branch 'master' into context

Moved extra_fonts/ to misc/fonts/. Moved .natvis file to misc/natvis/ (#1569)

Examples: Using Dark theme by default. (#707). Tweaked demo code.

Examples: Using #include "imgui.h" instead of <imgui.h> appear correct-er as per standard? xcode+clang are very nitpicky there.

Examples: Updated for reorganized context functions. Calling CreateContext(), DestroyContext() in example code. Removed Shutdown() from binding code. (#1565, #586, #992, #1007, #1558)

Examples: Vulkan: Tweak

Examples: Comments, synched some minor drift between examples + stronger suggestion to use StyleColorsDark().

Renamed the emblematic ShowTestWindow() function to ShowDemoWindow(). Kept redirection function (will obsolete).

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)

Examples: Added more comments near the fonts loading section, to catch common questions and errors (e.g. #1397, #1366, #1341, #1222, #1193, #1115, #951, etc.)

Examples: Adding Roboto to the commented-out font list, and removing the unnecessary ProggyClean from there.

Examples: Avoid using ImColor() to not tempt newcomers into looking at it

Examples: Main: Removed call to SetNextWindowSize()

Renamed ImGuiSetCond_XXX type and enums to ImGuiCond_XXX, kept old enums under #ifdef IMGUI_DISABLE_OBSOLETE_FUNCTIONS

Examples: Vulkan: Various very minor stylistic fixes, fixing typos in comments, etc. (#1042 #1043)

Image presentation now depends on the completeness of command buffer submission through semaphores. ...

To maintain maximum frame rate we render to the last acquired swapchain image but present the last but one drawn image. This behavior is optional through conditional compilation macros.

Removed redundant VkResult plugged into VkPresentInfoKHR pResults attribute. This is only meaningful when we present directly to multiple swapchains. In that case we can an VkResult per swapchain.

Removed redundant barrier. ...

The transition of the swapchain image(s) can happen implicitly in the renderpass. This approach has been stated to be more efficient than using an explicit barrier.
See "Vulkan Programming Guide", Chapter 7: "Graphics Pipelines", section "Renderpasses".

Fixed all issues found by vulkan debug report. Reasons for the major design changes are commented.

Examples: Vulkan: Disable IMGUI_VULKAN_DEBUG_REPORT by default. Update .bat files for newer VulkanSDK.

Vulkan backend: optionally enabling vulkan validation layers and debug report callback ...

Additional layer, extension and the callback itself are used/created when IMGUI_VULKAN_DEBUG_REPORT is defined. The callback reports seven (potential!) errors which will be fixed with another pull request.

typo, #elif instead of #else, fixed