Examples: Renamed applications to emphasis on use of GLFW as a platform framework + minor local tweaks

Examples: Vulkan: Fix missing subpass dependency ...

Without a dependency between pWaitDstStageMask (COLOR_ATTACHMENT_OUTPUT)
and the render-pass, the UNDEFINED -> COLOR_ATTACHMENT_OPTIMAL transition
might happen before the image is ready to be used.

Examples: Vulkan: Using VK_PRESENT_MODE_MAILBOX_KHR. Disable IMGUI_UNLIMITED_FRAME_RATE by default. Fixed warnings. (#1042)

Examples: Vulkan: Only resize swap chain and framebuffer once. (#1042)

Examples: Renamed glfw error callback for clarity.

Fixed resize window validation errors with removing frame prerender once and present last but one frame functionality. Frame rate is still similar.

Examples: Added Makefile for SDL+OpenGL2 example. (#1668)

Examples: OpenGL3: Added a way to override the glsl version number through the Init call. (#1667, #1466)

Renamed ImGuiStyleVar_Count_ to ImGuiStyleVar_COUNT for consistency with other enums. Added

Makefile: updated sdl_opengl3_example with all changes from #885.

Do not store compiled objects outside the project tree.

Define SOURCES instead of OBJS in Makefiles. ...

OBJS is still deduced from SOURCES, but this change gives better control
over where the object files get actually written.

Use make variables $@ and $^ where appropriate.

Ensure `make clean` is idempotent. ...

Prior to this, `make clean` would fail if the project was not already
fully built, and a second invokation would always fail.

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

Examples: Fix d749d49 missing the deletion code. (#1217)

Examples: OpenGL3: Create the VAO in the render function so the setup can more easily be used with multiple shared GL context. (#1217)

Examples: DirectX12: Tweaked assertion to more accurately represent what it wants to say. (#301)

Update README.txt

Examples: DirectX12: Fixed shutdown issue. (#301)

Examples: DirectX12: Merge, various styling tweaks, update for 1.60 wip, synchronized Win32 features with other examples. (#301)

Examples: DirectX12: Removed from current solution which is meant to be VS2010 compatible for now (will change soon).

Merge branch 'jdm3_master'

Examples: DirectX10, DirectX11: Simplified main example code.

Simplified .gitignore list

Examples: SDL: Using %SDL2_DIR% in the .vcproj instead of %SDL_DIR%, the earlier is more standard.

Examples: OpenGL: Cast call to glPolygonMode(). (#1628).

Examples: Mouse cursor handling comments/tweaks to homogenize. (#1495)

Examples: GLFW: Added support for mouse cursors (ImGui::GetMouseCursor() value and WM_SETCURSOR message handling). (#1495)

Examples: GLFW*: Renamed GLFW callbacks exposed in .h to not include GL2/GL3/Vulkan in their name.