Allow model_verison in driver namelist to be set again

[ekluzek]

model_version was commented out in the driver namelist_definition file over a year ago, because it pointed to the xml variable CCSM_REPOTAG which is no longer available. If this would be added back in again (but without the dependence on CCSM_REPOTAG it could be at least set manually by the user.

Here's the minimal change needed

Index: ../../src/drivers/mct/cime_config/namelist_definition_drv.xml
===================================================================
--- ../../src/drivers/mct/cime_config/namelist_definition_drv.xml   (revision 11032)
+++ ../../src/drivers/mct/cime_config/namelist_definition_drv.xml   (working copy)
@@ -290,8 +290,7 @@
     </values>
   </entry>

-<!--      CURRENTLY DOES NOT EXIST
-  <entry id="model_version" modify_via_xml="CCSM_REPOTAG">
+  <entry id="model_version">
     <type>char</type>
     <category>expdef</category>
     <group>seq_infodata_inparm</group>
@@ -302,7 +301,6 @@
       <value>unset</value>
     </values>
   </entry>
--->

   <entry id="username" modify_via_xml="USER">
     <type>char</type>

[jedwards4b]

Why are you opening an issue here? Move to esmci.

[billsacks]

Closing this; it should be in ESMCI if it's still needed.