Preparation for v0.5.0 release (#108)

Update version, and add changelog entry including upgrade instructions.

CHANGELOG.md

@@ -1,3 +1,66 @@
+## v 0.5.0 / 2017-11-14
+
+NOTE: This release breaks backward compatibility. `statsd_exporter` now uses
+a YAML configuration file. You must convert your mappings configuration to
+the new format when you upgrade. For example, the configuration
+
+```
+test.dispatcher.*.*.*
+name="dispatcher_events_total"
+processor="$1"
+action="$2"
+outcome="$3"
+job="test_dispatcher"
+
+*.signup.*.*
+name="signup_events_total"
+provider="$2"
+outcome="$3"
+job="${1}_server"
+```
+
+now has the format
+
+```yaml
+mappings:
+- match: test.dispatcher.*.*.*
+  help: "The total number of events handled by the dispatcher."
+  name: "dispatcher_events_total"
+  labels:
+    processor: "$1"
+    action: "$2"
+    outcome: "$3"
+    job: "test_dispatcher"
+- match: *.signup.*.*
+  name: "signup_events_total"
+  help: "The total number of signup events."
+  labels:
+    provider: "$2"
+    outcome: "$3"
+    job: "${1}_server"
+```
+
+The help field is optional.
+
+There is a [tool](https://github.com/bakins/statsd-exporter-convert) available to help with this conversion.
+
+* [CHANGE] Replace the overloaded "packets" metric (#106)
+* [CHANGE] Removed `-statsd.add-suffix` option flag #99. Users should remove
+  this flag when upgrading.  Metrics will no longer automatically include the
+  suffixes `_timer`  or `counter`. You may need to adjust any graphs that used
+  metrics with these suffixes.
+* [CHANGE] Reduce log levels #92. Many log events have been changed from error
+  to debug log level.
+* [CHANGE] Use YAML for configuration file #66. See note above about file format
+  conversion.
+* [IMPROVEMENT] Allow help text to be customized #87
+* [IMPROVEMENT] Add support for regex mappers #85
+* [IMPROVEMENT] Add TCP listener support #71
+* [IMPROVEMENT] Allow histograms for timer metrics #66
+* [IMPROVEMENT] Added support for sampling factor on timing events #28
+* [BUGFIX] Conflicting label sets no longer crash the exporter and will be
+  ignored. Restart to clear the remembered label set. #72
+
 ## v0.4.0 / 2017-05-12
 
 * [IMPROVEMENT] Improve mapping configuration parser #61

VERSION

@@ -1 +1 @@
-0.4.0
+0.5.0