Update Colvars to version 2021-08-06 (silence Coverity Scan warnings)

Also include PDF copy of the manual forgotten in previous PR.

lib/colvars/colvarcomp_volmaps.cpp

@@ -103,7 +103,7 @@ void colvar::map_total::calc_value()
 {
   colvarproxy *proxy = cvm::main()->proxy;
   int flags = is_enabled(f_cvc_gradient) ? colvarproxy::volmap_flag_gradients :
-    colvarproxy::volmap_flag_gradients;
+    colvarproxy::volmap_flag_null;
 
   if (atoms != NULL) {
     // Compute the map inside Colvars

lib/colvars/colvargrid.cpp

@@ -166,6 +166,14 @@ colvar_grid_gradient::colvar_grid_gradient(std::string &filename)
   }
 
   is >> nd;
+
+  if (nd > 50) {
+    cvm::error("Error: excessive number of dimensions in file \""+
+               filename+"\".  Please ensure that the file is not corrupt.\n",
+               INPUT_ERROR);
+    return;
+  }
+
   mult = nd;
   std::vector<cvm::real> lower_in(nd), widths_in(nd);
   std::vector<int>       nx_in(nd);

lib/colvars/colvars_version.h

@@ -1,3 +1,3 @@
 #ifndef COLVARS_VERSION
-#define COLVARS_VERSION "2021-08-03"
+#define COLVARS_VERSION "2021-08-06"
 #endif