sal-echo.yang contains strange characters

There are some UTF8 sequencies causing sal-echo.yang to produce java sources which crash javadoc under windows.

[ERROR] Failed to execute goal org.apache.maven.plugins:maven-javadoc-plugin:2.10.1:jar (attach-javadocs) on project model-flow-service: MavenReportException: Error while creating archive:

[ERROR] Exit code: 1 - C:\odldev\openflowplugin\model\model-flow-service\src\main\yang-gen-sal\org\opendaylight\yang\gen\v1\urn\opendaylight\echo\service\rev150305\SendEchoInput.java:41: error: unmappable character for encoding UTF-8

[ERROR] * Openflow echo request payload (arbirary-length data ??eld). The data ??eld

[ERROR] ^

[ERROR] C:\ odldev\openflowplugin\model\model-flow-service\src\main\yang-gen-sal\org\opendaylight\yang\gen\v1\urn\opendaylight\echo\service\rev150305\SendEchoInput.java:41: error: unmappable character for encoding UTF-8

[ERROR] * Openflow echo request payload (arbirary-length data ??eld). The data ??eld

[ERROR] ^

[ERROR]

[ERROR] Command line was: c:\ Java\jdk1.7.0_75\jre\..\bin\javadoc.exe @options @packages

[ERROR]

[ERROR] Refer to the generated Javadoc files in 'C:\\odldev\openflowplugin\model\model-flow-service\target\apidocs' dir.

[ERROR] -> [Help 1]