message: Update RPC spec to 5.1.1
diff: <?xml version="1.0" standalone="no"?>
  <?xml-stylesheet type="text/xml" href="protocol2html.xsl"?>
  -<interface name="SmartDeviceLink RAPI" version="5.1.0" minVersion="1.0" date="2019-03-18">
  +<interface name="SmartDeviceLink RAPI" version="5.1.0" minVersion="1.0" date="2019-03-19">
  <enum name="Result" internal_scope="base" since="1.0">
  <element name="SUCCESS">
  <description>The request succeeded</description>
  </param>
  <param name="serviceType" type="String" mandatory="true">
  - <description> The type of service that is to be offered by this app </description>
  + <description> The type of service that is to be offered by this app. See AppServiceType for known enum equivalent types. Parameter is a string to allow for new service types to be used by apps on older versions of SDL Core. </description>
  </param>
  <param name="serviceIcon" type="Image" mandatory="false">
  <description> The service has been deactivated as the primary service of its type</description>
  </element>
  <element name="MANIFEST_UPDATE">
  - <description> The service has updated its manifest. This could imply updated capabilities. Note: Currently unimplemented </description>
  + <description> The service has updated its manifest. This could imply updated capabilities</description>
  </element>
  </enum>
  <element name="DISALLOWED"/>
  <element name="WARNINGS"/>
  </param>
  +
  + <param name="info" type="String" maxlength="1000" mandatory="false" platform="documentation">
  + <description>Provides additional human readable info regarding the result.</description>
  + </param>
  </function>
  <function name="GetCloudAppProperties" functionID="GetCloudAppPropertiesID" messagetype="request" since="5.1">
  <element name="DISALLOWED"/>
  <element name="WARNINGS"/>
  </param>
  +
  + <param name="info" type="String" maxlength="1000" mandatory="false" platform="documentation">
  + <description>Provides additional human readable info regarding the result.</description>
  + </param>
  </function>
  <function name="PublishAppService" functionID="PublishAppServiceID" messagetype="request" since="5.1">
  