Set LANG to UTF-8 in Launch Agent property list

As noted in the `pbcopy` man page, in the absence of a LANG environment
variable setting, `pbcopy` uses the standard C encoding. UTF-8, however,
is recommended. As this seems a reasonable default, let's stick it in
the property list.

Fixes:

  https://wincent.com/issues/2119

Signed-off-by: Wincent Colaiuta <win@wincent.com>

Author: wincent

com.wincent.clipper.plist

@@ -12,6 +12,11 @@
 		<string>--port</string>
 		<string>8377</string>
 	</array>
+	<key>EnvironmentVariables</key>
+	<dict>
+		<key>LANG</key>
+		<string>en_US.UTF-8</string>
+	</dict>
 	<key>KeepAlive</key>
 	<true/>
 	<key>LimitLoadToSessionType</key>