Issue: #96 - Garbage collect inodeproc once every 50 ui refresh as default.

- Reduce default frequency to avoid performance issue.
- The frequency of it can be modified with `-g` option
  and can be disabled with `-g 0`.

doc/nethogs.8

@@ -19,6 +19,7 @@ nethogs \- Net top tool grouping bandwidth per process
 .RB [ "\-l" ]
 .RB [ "\-f filter" ]
 .RB [ "\-C" ]
+.RB [ "\-g period" ]
 .RI [device(s)]
 .SH DESCRIPTION
 NetHogs is a small 'net top' tool. Instead of breaking the traffic down per protocol or per subnet, like most such tools do, it groups bandwidth by process - and does not rely on a special kernel module to be loaded. So if there's suddenly a lot of network traffic, you can fire up NetHogs and immediately see which PID is causing this, and if it's some kind of spinning process, kill it.
@@ -61,6 +62,9 @@ monitor all devices, even loopback/stopped ones.
 \fB-C\fP
 capture TCP and UDP.
 .TP
+\fB-g\fP
+garbage collection period in number of refresh. default is 50.
+.TP
 \fB-f\fP
 EXPERIMENTAL: specify string pcap filter (like tcpdump). This may be removed or changed in a future version.
 .TP