[svn-r24057] Add --superblock long name to parser and add tests for both --boot-block and --superblock.

Tested: local linux

tools/testfiles/tboot2A.ddl

@@ -0,0 +1,20 @@
+HDF5 "tfcontents2.h5" {
+SUPER_BLOCK {
+   SUPERBLOCK_VERSION 0
+   FREELIST_VERSION 0
+   SYMBOLTABLE_VERSION 0
+   OBJECTHEADER_VERSION 0
+   OFFSET_SIZE 8
+   LENGTH_SIZE 8
+   BTREE_RANK 16
+   BTREE_LEAF 4
+   ISTORE_K 32
+   FILE_SPACE_STRATEGY H5F_FILE_SPACE_ALL
+   FREE_SPACE_THRESHOLD 1
+   USER_BLOCK {
+      USERBLOCK_SIZE 0
+   }
+}
+GROUP "/" {
+}
+}