Corrected the check_density.py script to add a timeout value of 1/2
second on the select.select() call to keep it from causing the
outer script to take up 100% CPU cycles while the magic subprocess
runs.

scripts/check_density.py

diff --git a/scripts/check_density.py b/scripts/check_density.py
index 7dceb44..f9e1ad4 100755
--- a/scripts/check_density.py
+++ b/scripts/check_density.py
@@ -259,7 +259,7 @@
                     status = mproc.poll()
                     if status != None:
                         break
-                sresult = select.select([mproc.stdout, mproc.stderr], [], [], 0)[0]
+                sresult = select.select([mproc.stdout, mproc.stderr], [], [], 0.5)[0]
                 if mproc.stdout in sresult:
                     outstring = mproc.stdout.readline().strip()
                     dlines.append(outstring)