In a TYP file the section indexes need to be sorted by type.

git-svn-id: http://svn.mkgmap.org.uk/mkgmap/trunk@2438 25d90789-57f7-4ee0-8453-03a3dfeeeb22
Remove tdb-v3 option and now a tdbfile is always created even when there
is only one input file.

The interaction between --index and --tdbfile is still as before. In other words --tdbfile is not
truly set by default.

git-svn-id: http://svn.mkgmap.org.uk/mkgmap/trunk@2439 25d90789-57f7-4ee0-8453-03a3dfeeeb22