* etags.c [TeX_named_tokens]: Set to FALSE if undefined.

* etags.c [TeX_named_tokens]: Set to FALSE if undefined.
	(struct linebuffer): New member `len' is the length of the string.
	(find_entries, Pascal_functions, TeX_functions, TEX_getit):
	Use it instead of strlen.
	(TEX_getit): Declare and define unconditionally as static.
	(TeX_functions): Use if instead of #if TeX_named_tokens.
	(add_regex): Set RE_INTERVALS flag for regex compilation.
	(substitute): Code cleanup.
	(readline_internal): Code cleanup, set new member `len'.
	(readline): Bug corrected.