add write_data support, for testing

also refactor label map initialization, memory cleanup

src/write_data.cpp

@@ -24,6 +24,7 @@
 #include "fix.h"
 #include "force.h"
 #include "improper.h"
+#include "label_map.h"
 #include "memory.h"
 #include "modify.h"
 #include "output.h"
@@ -188,6 +189,10 @@ void WriteData::write(const std::string &file)
     if (coeffflag) force_fields();
   }
 
+  // label map before Atoms, Bonds, etc.
+
+  if (me == 0) atom->lmap->write_data(fp); // NOTE: always write for now, for testing
+
   // per atom info in Atoms and Velocities sections
 
   if (natoms) atoms();