Remove the mastefile-format map option

As previously announced, this commit removes the masterfile-format
format 'map' from named, all the tools, the documentation and the
system tests.

bin/tests/system/checkconf/bad-maxratio2.conf

@@ -11,7 +11,7 @@
 
 zone example {
 	type master;
-	masterfile-format map;
+	masterfile-format raw;
 	file "example.db";
 	max-ixfr-ratio 0%;
 };