Update README.txt

Update README.txt

Use ImGuiIO::AddInputCharactersUTF8() in SDL2 example ...

Now Unicode text input works in this example.

Fix SDL2-example for Linux ...

The header is called "SDL_opengl.h" - case matters on Linux.

The main() function must indeed be called main(), on Windows it'll be
renamed to SDL_main (for SDL2main.lib) by #define in SDL_main.h
(which is included by SDL.h)

I added an entry to the example's README that describes how to build
it on Linux.

Fonts: added Cousine-Regular.ttf

Examples: comments.

Examples: Simplified font examples comments.

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

Conflicts:
	imgui.cpp

Examples: README

Allegro 5 example: removed public domain mark, MIT as the rest, with @bggd approval

Allegro 5 example: converted for indexed rendering.

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

Allegro 5 example: fixed uv coordinate of non-default texture.

Allegro 5 example: handling of hardware and software mouse cursor rendering.

Allegro 5 example: fixed key modifiers, keyboard input, clipping, added pagedown/pageup.

Allegro 5 example: formatting, match other example structure, fixed mouse buttons.

Allegro 5 example: main.cpp matches other examples. added window title.

SDL example: tweaks (#233 #226)

Allegro5 example: added example from https://github.com/bggd/a5imgui_example

SDL example: hasty readme.

Merge branch '2015-03-antialiased-primitives' of https://github.com/ocornut/imgui into 2015-03-antialiased-primitives

SDL example: update for indexed rendering.

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

Merge pull request #264 from joeld42/antialias-ios-fix ...

AA branch: iOS Example: update for API changes and index rendering

SDL example: more cleanup to match other examples (#233 #226)

SDL example: further cleanup to match other examples (#233 #226)

SDL example: moved event loop to main.cpp , adding page up/page down. (#226)

Simplified to not combine vert buffers like the opengl3 example

SDL example: renamed folder, added in README

SDL example: tweaks and fixes.