ylwrap: various fixes Rename properly header guards in generated header files, instead of leaving Y_TAB_H. Convert header guards in implementation files. Because ylwrap failed to rename properly #include in the implementation files, current versions of Bison (e.g., 2.7) duplicate the generated header file in the implementation file. The header guard then protects the implementation file from duplicate definitions from the header file. Generate header guards with a single '_' for series of non alphabetic characters, instead of several. This is what Bison does. Makes the test t/yacc-d-basic.sh pass again. * lib/ylwrap (guard): Properly honor $1 to rename properly the header guards. Keep a single _ instead of several. (rename_sed): Rename as... (sed_fix_filenames): this. Suggested by Stefano Lattarini. (sed_fix_header_guards): New. Use it.