* src/getargs.h, src/getargs.c (trace_e, trace_args, trace_types):

* src/getargs.h, src/getargs.c (trace_e, trace_args, trace_types):
Add support for --trace=skeleton.
* src/scan-skel.l: %option debug.
Scan strings of non-@ or n instead of character by character.
(scan_skel): Handle trace_skeleton.
(QPUTS): New.
(@output_parser_name@, @output_header_name@): ``Restore'' their
support (used to be M4 macros).
* data/yacc.c: Quote larger chunks, a la glr.c.
* data/lalr1.cc: Likewise.
The header guards are no longer available, so use some other
string than `YYLSP_NEEDED'.