* etags.c (C_entries): Initialise the new members of TOKEN.
(C_entries): Do not allocate a new space for each token found by
consider_token. Let make_tag do that instead.
(make_tag): Since now TOKEN has memory of where it is taken from,
this new macro substitutes both make_tag_from_new_lb and
make_tag_from_oth_lb. All callers changed.
(TOKEN): Add linepos and buffer members.
(main): Initialise token_str.
(lang_extensions): Recognise .c++ and .h++ as C++ file suffixes.
(token_str): New global variable used by C_entries.