[EXIT_SUCCESS, EXIT_FAILURE]: Define them when no

[EXIT_SUCCESS, EXIT_FAILURE]: Define them when no
<stdlib.h> is available.
(enum sym_type): New st_C_attribute value for parsing
gcc's __attribute__.  Deleted st_C_typespec value.
(gperf, in_word_set): Use gperf 3, options changed.  Added the
__attribute__ keyword, removed all the st_C_typespec keywords,
changed attribute for Java to (C_JAVA & !C_PLPL).
(inattribute): New global bool, part of the C state machine.
(cblev): Identifier renamed to bracelev throughout.
(consider_token, C_entries): Numerous changes for making the
parser more robust and adding support for __attribute__.

Tiny change by David A. Capello <dacap@users.sourceforge.net> -
(Lua_suffixes, Lua_help, lang_names, Lua_functions):
Support the Lua scripting language <http://www.lua.org>.