Merge pull request #2742 from bertinia/maint-5.6-component-return-values

updates for compatibility with XML to html tools
These are updates to cime based classes in support of the XML to HTML
auto-generation tools in https://github.com/NCAR/CESM_xml2html.
Also minor update to DOCN config_component.xml to correct invalid ASCII character.

Test suite: scripts_regression_tests.py B_CheckCode
Test baseline: N/A
Test namelist changes: N/A
Test status: bit for bit

Fixes [CIME Github issue #]

User interface changes?: None

Update gh-pages html (Y/N)?: N

Code review:jedwards

driver-mct/cime_config/config_component.xml

@@ -626,15 +626,6 @@
     Must be explicitly set in env_build.xml for userdefined machine.</desc>
   </entry>
 
-  <entry id="SUPPORTED_BY">
-    <type>char</type>
-    <valid_values></valid_values>
-    <default_value></default_value>
-    <group>build_def</group>
-    <file>env_build.xml</file>
-    <desc>email address of person (or group) that supports the build and port for this machine (do not edit)></desc>
-  </entry>
-
   <entry id="MPILIB">
     <type>char</type>
     <valid_values></valid_values>