Add new grid aliases for gx3v7 and usgs masks. This is being done to

match the new grid alias style that includes the masks, mg16, mg17,
mg37, mgusgs.

Test suite: scripts_regression_test
Test baseline:
Test namelist changes:
Test status: bit for bit

Fixes #1498

User interface changes?:

Code review:

config/cesm/config_grids.xml

@@ -176,13 +176,27 @@
       <mask>usgs</mask>
     </model_grid>
 
+    <model_grid alias="T42_T42_musgs" not_compset="_POP">
+      <grid name="atm">T42</grid>
+      <grid name="lnd">T42</grid>
+      <grid name="ocnice">T42</grid>
+      <mask>usgs</mask>
+    </model_grid>
+
     <model_grid alias="T85_T85" not_compset="_POP">
       <grid name="atm">T85</grid>
       <grid name="lnd">T85</grid>
       <grid name="ocnice">T85</grid>
       <mask>usgs</mask>
     </model_grid>
 
+    <model_grid alias="T85_T85_musgs" not_compset="_POP">
+      <grid name="atm">T85</grid>
+      <grid name="lnd">T85</grid>
+      <grid name="ocnice">T85</grid>
+      <mask>usgs</mask>
+    </model_grid>
+
     <model_grid alias="T85_f09_t12">
       <grid name="atm">T85</grid>
       <grid name="lnd">0.9x1.25</grid>
@@ -607,20 +621,34 @@
       <mask>gx3v7</mask>
     </model_grid>
 
+    <model_grid alias="f45_f45_mg37" not_compset="_POP">
+      <grid name="atm">4x5</grid>
+      <grid name="lnd">4x5</grid>
+      <grid name="ocnice">4x5</grid>
+      <mask>gx3v7</mask>
+    </model_grid>
+
     <model_grid alias="f10_f10" not_compset="_POP">
       <grid name="atm">10x15</grid>
       <grid name="lnd">10x15</grid>
       <grid name="ocnice">10x15</grid>
       <mask>usgs</mask>
     </model_grid>
+
+    <model_grid alias="f10_f10_musgs" not_compset="_POP">
+      <grid name="atm">10x15</grid>
+      <grid name="lnd">10x15</grid>
+      <grid name="ocnice">10x15</grid>
+      <mask>usgs</mask>
+    </model_grid>
 
     <!--  spectral element grids -->
 
     <model_grid alias="ne16_g37">
       <grid name="atm">ne16np4</grid>
       <grid name="lnd">ne16np4</grid>
       <grid name="ocnice">gx3v7</grid>
-      <mask>gx3v6</mask>
+      <mask>gx3v7</mask>
     </model_grid>
 
     <model_grid alias="ne30_g16">
@@ -734,6 +762,13 @@
       <mask>gx3v7</mask>
     </model_grid>
 
+    <model_grid alias="ne16_ne16_mg37" not_compset="_POP">
+      <grid name="atm">ne16np4</grid>
+      <grid name="lnd">ne16np4</grid>
+      <grid name="ocnice">ne16np4</grid>
+      <mask>gx3v7</mask>
+    </model_grid>
+
     <model_grid alias="ne30_ne30" not_compset="_POP">
       <grid name="atm">ne30np4</grid>
       <grid name="lnd">ne30np4</grid>