[client] doc: update README.md with new libraries and backend config

client/README.md

@@ -17,10 +17,12 @@ This is the Looking Glass client application that is designed to work in tandem
 * libfontconfig1-dev
 * libx11-dev
 * nettle-dev
+* libxss-dev
+* libxi-dev
 
 #### Debian (and maybe Ubuntu)
 
-    apt-get install binutils-dev cmake fonts-freefont-ttf libsdl2-dev libsdl2-ttf-dev libspice-protocol-dev libfontconfig1-dev libx11-dev nettle-dev
+    apt-get install binutils-dev cmake fonts-freefont-ttf libsdl2-dev libsdl2-ttf-dev libspice-protocol-dev libfontconfig1-dev libx11-dev nettle-dev libxss-dev libxi-dev
 
 ### Building
 
@@ -31,6 +33,19 @@ This is the Looking Glass client application that is designed to work in tandem
 
 Should this all go well you should be left with the file `looking-glass-client`
 
+### Removing Wayland or X11 support
+
+Wayland and/or X11 support can be disabled with the compile options
+`ENABLE_WAYLAND` and `ENABLE_X11`, if both are specified only `SDL2` will remain
+and the client will fallback to using it.
+
+    cmake ../ -DENABLE_WAYLAND=OFF
+
+At this time, X11 is the perferred and best supported interface. Wayland is not
+far behind, however it lacks some of the seamless interaction features that X11
+has due to the lack of cursor warp (programmatic movement of the local cusror) on
+Wayland.
+
 ---
 
 ## Usage Tips