Merge branch 'develop' into collected-small-changes

# Conflicts:
#	python/lammps/pylammps.py

python/lammps/pylammps.py

@@ -544,6 +544,18 @@ class PyLammps(object):
     """
     self._cmd_history = []
 
+
+  def append_cmd_history(self, cmd):
+    """
+    Commands will be added to the command history but not executed.
+
+    Add `commands` only to the command history, but do not execute them, so that you can
+    conveniently create Lammps input files, using
+    :py:meth:`PyLammps.write_script()`.
+    """
+    self._cmd_history.append(cmd)
+
+
   def command(self, cmd):
     """
     Execute LAMMPS command