* strace.cc (main): Change getopt() to getopt_long().

	* strace.cc (main): Change getopt() to getopt_long().
	Add support for help and version info.
	Use new parse_mask() function for -m/--mask option.
	(longopts): Add long options structure.
	(opts): Move options string from getopts call to static var.
	(usage): Print usage information.
	(SCCSid): Version info.
	(version): New function for displaying version info.
	(parse_mask): New function supporting parsing of mnemonics,
	hex, and basic expressions in masks.
	(mnemonic2ul): New mnemonic parsing function.
	(tag_mask_mnemonic): New type.
	(mnemonic_table): New table of mnemonics for mnemonic2ul() to
	search through.