Category Tree: Reduce number of categories

mogilefs -> fs (mogilefs)
moodle -> cms (moodle)
openvz -> virtualization (openvz)
wowza -> streaming (wowza)
varnish -> webserver (varnish)
xbnbt -> torrent (xbnbt)

plugins/varnish/README-varnish4.md

@@ -0,0 +1,33 @@
+Munin Plugin for Varnish 4
+==========================
+
+Modified version of the plugin for Varnish 2/3 from the munin distribution
+to adapt to the XML output of Varnish 4 varnishstat.
+
+Installation
+------------
+
+- Copy `varnish4_` to the Munin plugins directory (`/usr/share/munin/plugins/`)
+- Make `varnish4_` runnable (`chmod +x /usr/share/munin/plugins/varnish4_`)
+
+Configuration
+-------------
+
+Run `munin-node-configure --shell` and link the aspects to monitor to
+your actual plugins directory.
+
+In your plugins.conf add
+```
+[varnish4_*]
+     group varnish
+     env.varnishstat varnishstat
+     env.name
+```
+`group varnish` Since Varnish version 4.1, Varnish shared log utilities must be run in a context with *varnish* group membership.
+
+`env.varnishstat` can be a full path to varnishstat if it's
+not in the path already.
+
+`env.name` is blank (undefined) by default and can be used to specify a -n
+name argument to varnish if multiple instances are running on the same
+server. 

plugins/varnish/varnish2_

@@ -50,7 +50,7 @@ if ($config) {
     print "graph_title Varnish $grepfor usage\n";
     print "graph_args --base 1000\n";
     print "graph_vlabel Activity / \${graph_period}\n";
-    print "graph_category Varnish\n";
+    print "graph_category webserver\n";
 }
 
 $i = 0;

plugins/varnish/varnish_devicedetect

@@ -63,7 +63,7 @@ export devices
 print_config() {
   printf "graph_title Varnish device detection\n"
   printf "graph_vlabel percent\n"
-  printf "graph_category varnish\n"
+  printf "graph_category webserver\n"
   printf "graph_args --rigid --lower-limit 0 --upper-limit 100\n"
 
   for device in $devices; do