Examples: DirectX9: resizing vertex and index buffers dynamically (#299)

AA branch: Agressively renamed all fields of ImDrawList, ImDrawCmd, ImDrawData to match the rest of our coding convention (#133)

Merge remote-tracking branch 'origin' into 2015-03-antialiased-primitives ...

Conflicts:
	examples/directx11_example/imgui_impl_dx11.cpp
	examples/directx9_example/imgui_impl_dx9.cpp
	examples/opengl3_example/imgui_impl_glfw_gl3.cpp
	examples/opengl_example/imgui_impl_glfw.cpp
	imgui.cpp

Removed the majority of size_t from the code. ImVector<> now uses int. (#262) ...

May trigger new compilation warnings?

AA branch: ImDrawList: rename commands to cmd_buffer ...

Not strictly necessary but while we're doing minor breakage let's do
them at all once.

AA branch: ImDrawCmd idx_count -> elem_count

AA branch: io.RenderDrawListsFn signature changed to take ImDrawData, neater and future proof breaking of the render API (#133 #254)

Examples: DirectX9: fixed size passed to vertex and index buffer Lock() + readjust default buffer sizes.

Merge remote-tracking branch 'origin' into 2015-03-antialiased-primitives

Added ImGuiKey_PageUp, ImGuiKey_PageDown for user.

Fixed warnings for 64-bits builds

Merge remote-tracking branch 'origin' into 2015-04-indexed-rendering ...

Conflicts:
	imgui.cpp
	imgui.h

ImFontAtlas: doesn't clear input data, left to the application. (#224)

Merge remote-tracking branch 'origin' into 2015-04-indexed-rendering

Examples: DirectX9/11: hide os curosr if ImGui is drawing it (#155)

Examples: DirectX9/11: Fixed key mapping for down arrow.

Indexed rendering. Not in main branch because breaks rendering code too much. Will merge in trunk along with more major graphics changes lat

Examples: Formatting #187

set pixel shader and vertex shader to NULL ...

Previous graphic render may use shaders,so set pixel shader and vertex shader to NULL to force use fixed pipeline.

Examples: DirectX9: fixed duplicate creation of vertex buffer. Size of static vertex buffer at top of the code.

Examples: Fixed Clang warnings in DirectX examples

Examples: MSVC: increase warning level from /W3 to /W4 for DirectX examples

Added io.KeyAlt + support in examples apps ...

Currently unused but supported by sample so that more people will have
it set up when menus needs them

Examples: reference implementations honors drawlist user callbacks.

Examples: DirectX9 example cleanup to match DirectX11 structure.

Examples: DirectX9 example application handle window resizing.

Examples: Refactored directx11_example to be easier to copy & paste into user application.

Examples: Tweaks.

Examples: Refactored directx9_example to be eaasier to copy & paste into user application.