collectd: update to 5.5.0

Update collectd, base of Luci statistics, to 5.5.0.

Patches have been refreshed.
write-graphite plugin is now enabled. (see #1351)

I have compile-tested all plugins with ar71xx,
and real-life tested the following plugins:
Conntrack, Processor (CPU), DNS, Interfaces, Wireless, System Load,
Memory, Ping, Uptime

Signed-off-by: Hannu Nyman <hannu.nyman@iki.fi>

utils/collectd/patches/140-fix-fqdnlookup.patch

@@ -1,6 +1,6 @@
---- a/src/configfile.c
-+++ b/src/configfile.c
-@@ -105,7 +105,7 @@ static cf_global_option_t cf_global_opti
+--- a/src/daemon/configfile.c
++++ b/src/daemon/configfile.c
+@@ -109,7 +109,7 @@ static cf_global_option_t cf_global_opti
  	{"BaseDir",     NULL, PKGLOCALSTATEDIR},
  	{"PIDFile",     NULL, PIDFILE},
  	{"Hostname",    NULL, NULL},