Added possibility to use replica exchange from fortran

The interface to set replica communicator from fortran was missing.

CHANGES/v2.0.txt

@@ -18,7 +18,11 @@ In addition, it is now much easier to contribute new functionality to the code b
 - Developer and user documentation 
 
 Version 2.0.1 (unpublised yet, check out branch v2.0 on git repository)
+For users:
 - Several small fixes in documentation and log file
 - Added message when "plumed simpled" is used on a non-existing file
+For developers:
+- Several small fixes in documentation
+- Added possibility to setup replica exchange from MD codes in fortran (commands "GREX setMPIFIntercomm" and "GREX setMPIFIntracomm")
 
 */

src/core/GREX.cpp

@@ -66,6 +66,13 @@ void GREX::cmd(const string&key,void*val){
     CHECK_NOTINIT(initialized,key);
     intercomm.Set_comm(val);
     plumedMain.multi_sim_comm.Set_comm(val);
+  }else if(key=="setMPIFIntracomm"){
+    CHECK_NOTINIT(initialized,key);
+    intracomm.Set_fcomm(val);
+  }else if(key=="setMPIFIntercomm"){
+    CHECK_NOTINIT(initialized,key);
+    intercomm.Set_fcomm(val);
+    plumedMain.multi_sim_comm.Set_fcomm(val);
   }else if(key=="init"){
     CHECK_NOTINIT(initialized,key);
     initialized=true;