Implement putting clients onto specific workspaces ("assign" in the configfile)

This closes ticket #39

docs/userguide

@@ -0,0 +1,59 @@
+i3 User’s Guide
+===============
+Michael Stapelberg <michael+i3@stapelberg.de>
+May 2009
+
+This document contains all information you need to configuring and using the i3 window
+manager. If it does not, please contact me on IRC, Jabber or E-Mail and I’ll help you out.
+
+== Configuring i3
+
+TODO: document the other options, implement variables before
+
+terminal::
+	Specifies the terminal emulator program you prefer. It will be started by default when
+	you press Mod1+Enter, but you can overwrite this. Refer to it as +$terminal+ to keep things
+	modular.
+font::
+	Specifies the default font you want i3 to use. Use an X core font descriptor here, like
+	+-misc-fixed-medium-r-normal--13-120-75-75-C-70-iso10646-1+. You can use +xfontsel(1)+
+	to pick one.
+
+=== Keyboard bindings
+
+TODO
+
+*Syntax*:
+--------------------------------
+bind [Modifiers+]keycode command
+--------------------------------
+
+*Examples*:
+--------------------------------
+# Fullscreen
+bind Mod1+41 f
+
+# Restart
+bind Mod1+Shift+27 restart
+--------------------------------
+
+=== Automatically putting clients on specific workspaces
+
+It is recommended that you match on window classes whereever possible because some applications
+first create their window and then care about setting the correct title. Firefox with Vimperator
+comes to mind, as the window starts up being named Firefox and only when Vimperator is loaded,
+the title changes. As i3 will get the title as soon as the application maps the window (mapping
+means actually displaying it on the screen), you’d need to have to match on Firefox in this case.
+
+*Syntax*:
+----------------------------------------------------
+assign ["]window class[/window title]["] [→] workspace
+----------------------------------------------------
+
+*Examples*:
+----------------------
+assign urxvt 2
+assign urxvt → 2
+assign "urxvt" → 2
+assign "urxvt/VIM" → 3
+----------------------