Added save in Fame databases.

*Example*

>> ts = dseries(randn(200, 30), dates('1950Q1'));
>> ts.save('toto','fame')

The last command will save all the time series in a Fame database called
toto.db.

src/@dseries/save.m

@@ -91,6 +91,10 @@ switch format
         fprintf(fid, '%s%s\n',date2string(A.dates(t)),str);
     end
     fclose(fid);
+  case 'fame'
+    fame.write([basename '.db'], A);
+  otherwise
+    error('Unknown format!')
 end
 
 %@test:1