re PR fortran/18540 (Jumping into blocks gives error rather than warning)

PR fortran/18540
PR fortran/18937
* gfortran.h (BBT_HEADER): Move definition up.
(gfc_st_label): Add BBT_HEADER, remove 'prev' and 'next'.
* io.c (format_asterisk): Adapt initializer.
* resolve.c (resolve_branch): Allow FORTRAN 66 cross-block GOTOs
as extension.
* symbol.c (compare_st_labels): New function.
(gfc_free_st_label, free_st_labels, gfc_get_st_label): Convert to
using balanced binary tree.
* decl.c (match_char_length, gfc_match_old_kind_spec): Do away
with 'cnt'.
(warn_unused_label): Adapt to binary tree.
* match.c (gfc_match_small_literal_int): Only set cnt if non-NULL.
* primary.c (match_kind_param): Do away with cnt.

Also converted the ChangeLog to use latin1 characters.

From-SVN: r109914