Convert ipmi stats/tags to underscore and lowercase

closes #888

plugins/inputs/ipmi_sensor/README.md

@@ -0,0 +1,42 @@
+# Telegraf ipmi plugin
+
+Get bare metal metrics using the command line utility `ipmitool`
+
+see ipmitool(https://sourceforge.net/projects/ipmitool/files/ipmitool/)
+
+The plugin will use the following command to collect remote host sensor stats:
+
+ipmitool -I lan -H 192.168.1.1 -U USERID -P PASSW0RD sdr
+
+## Measurements
+
+- ipmi_sensor:
+
+    * Tags: `name`, `server`, `unit`
+    * Fields:
+      - status
+      - value
+
+## Configuration
+
+```toml
+[[inputs.ipmi]]
+  ## specify servers via a url matching:
+  ##  [username[:password]@][protocol[(address)]]
+  ##  e.g.
+  ##    root:passwd@lan(127.0.0.1)
+  ##
+  servers = ["USERID:PASSW0RD@lan(10.20.2.203)"]
+```
+
+## Output
+
+```
+> ipmi_sensor,server=10.20.2.203,unit=degrees_c,name=ambient_temp status=1i,value=20 1458488465012559455
+> ipmi_sensor,server=10.20.2.203,unit=feet,name=altitude status=1i,value=80 1458488465012688613
+> ipmi_sensor,server=10.20.2.203,unit=watts,name=avg_power status=1i,value=220 1458488465012776511
+> ipmi_sensor,server=10.20.2.203,unit=volts,name=planar_3.3v status=1i,value=3.28 1458488465012861875
+> ipmi_sensor,server=10.20.2.203,unit=volts,name=planar_vbat status=1i,value=3.04 1458488465013072508
+> ipmi_sensor,server=10.20.2.203,unit=rpm,name=fan_1a_tach status=1i,value=2610 1458488465013137932
+> ipmi_sensor,server=10.20.2.203,unit=rpm,name=fan_1b_tach status=1i,value=1775 1458488465013279896
+```