explained how to clean up the resizR directory, while the daemon is r…

…unning.

README.txt

@@ -46,6 +46,11 @@ is python code itself and resizR will execute anything in the global namespace
 of the config file on startup, so be sure what you are doing, if you change the
 file beyond the settings that are provided by default.
 
+To prevent your resizR directory from cluttering up, you can force resizR to
+clean it up while running, by sending SIGUSR1 to the python process. This will
+delete the entire resizR directory and recreate the directories for the
+different sizes.
+
 You can run resizR from the checked out git repo or you can run the setup.py
 program to install it locally into /usr/bin + its modules in the site-packages
 directory of your python installation. The easiest way to use resizR is to put