Bug 798810 - Income Statement (multicolumn) - account sorting is...

'reversed' each time you restart.

Lists read from the front, vectors to the back, so reverse the
vector after loading it.

While we're at it reserve enough elements to hold the list.

bindings/guile/gnc-optiondb.i

@@ -466,6 +466,9 @@ scm_to_value<GncOptionAccountList>(SCM new_value)
     GncOptionAccountList retval{};
     if (scm_is_false(scm_list_p(new_value)) || scm_is_null(new_value))
         return retval;
+
+    retval.reserve(scm_to_size_t(scm_length(new_value)));
+
     auto next{new_value};
     while (!scm_is_null(next) && scm_car(next))
     {
@@ -491,6 +494,8 @@ scm_to_value<GncOptionAccountList>(SCM new_value)
         }
         next = scm_cdr(next);
     }
+
+    std::reverse(retval.begin(), retval.end());
     return retval;
 }