Adding alternative names of terminal nucleic acids (5' and 3' as DG5 and DG3)....

Adding alternative names of terminal nucleic acids (5' and 3' as DG5 and DG3). Adding alternative names of atoms H2', H2'', H5' and H5'' for nucleic acids.

wrappers/python/simtk/openmm/app/data/pdbNames.xml

@@ -25,12 +25,12 @@
   <Atom name="O4'" alt1="O4*"/>
   <Atom name="O5'" alt1="O5*"/>
   <Atom name="H1'" alt1="H1*"/>
-  <Atom name="H2'" alt1="H2*" alt2="1H2*" alt3="1H2'"/>
-  <Atom name="H2''" alt1="2H2*" alt2="2H2'"/>
+  <Atom name="H2'" alt1="H2*" alt2="1H2*" alt3="1H2'" alt4="H2'1"/>
+  <Atom name="H2''" alt1="2H2*" alt2="2H2'" alt3="H2'2"/>
   <Atom name="H3'" alt1="H3*"/>
   <Atom name="H4'" alt1="H4*"/>
-  <Atom name="H5'" alt1="1H5*" alt2="1H5'"/>
-  <Atom name="H5''" alt1="2H5*" atl2="2H5'"/>
+  <Atom name="H5'" alt1="1H5*" alt2="1H5'" alt3="H5'1"/>
+  <Atom name="H5''" alt1="2H5*" atl2="2H5'" alt3="H5'2"/>
   <Atom name="HO2'" alt1="2HO*"/>
   <Atom name="HO3'" alt1="H3T"/>
   <Atom name="HO5'" alt1="H5T"/>
@@ -252,19 +252,19 @@
   <Atom name="H42" alt1="2H4"/>
  </Residue>
  <Residue name="U" alt1="URA" type="Nucleic"/>
- <Residue name="DA" alt1="DAD" type="Nucleic">
+ <Residue name="DA" alt1="DAD" alt2="DA3" alt3="DA5" type="Nucleic">
   <Atom name="H61" alt1="1H6"/>
   <Atom name="H62" alt1="2H6"/>
  </Residue>
- <Residue name="DG" alt1="DGU" type="Nucleic">
+ <Residue name="DG" alt1="DGU" alt2="DG3" alt3="DG5" type="Nucleic">
   <Atom name="H21" alt1="1H2"/>
   <Atom name="H22" alt1="2H2"/>
  </Residue>
- <Residue name="DC" alt1="DCY" type="Nucleic">
+ <Residue name="DC" alt1="DCY" alt2="DC3" alt3="DC5" type="Nucleic">
   <Atom name="H41" alt1="1H4"/>
   <Atom name="H42" alt1="2H4"/>
  </Residue>
- <Residue name="DT" alt1="THY" type="Nucleic">
+ <Residue name="DT" alt1="THY" alt2="DT3" alt3="DT5" type="Nucleic">
   <Atom name="C7" alt1="C5M"/>
   <Atom name="H71" alt1="1H5M"/>
   <Atom name="H72" alt1="2H5M"/>