added 'SetXProp' action and (@PROP=foo) clientpattern

these two allow 'tagging' of arbitrary windows with 'tags' (or 'labels'). such 'tagged' windows can then be used in ':NextWindow (@PROP=foo)' commands to quickly cycle through a subset of available windows.
since the 'tags' are applied as real xproperties to a window they survive a restart of fluxbox or even another windowmanager. the user can also set the tags by using xprop(1).

the next step regarding the UI should be to visualize the tags of a window.

1 files changed, 2 insertions, 0 deletions

diff --git a/src/Focusable.hh b/src/Focusable.hh
index 47f14d3..4583a62 100644
--- a/src/Focusable.hh
+++ b/src/Focusable.hh
@@ -88,6 +88,8 @@ public:
     /// @return wm role string (for pattern matching)
     virtual std::string getWMRole() const { return "Focusable"; }
 
+    virtual FbTk::FbString getTextProperty(Atom prop) const { return ""; }
+
     /// @return whether this window is a transient (for pattern matching)
     virtual bool isTransient() const { return false; }