define _XOPEN_SOURCE so prototype of posix_memalign loads
remove trailing comma
use explicit size calculations for structure hack
more definitions of string functions
prototypes for string functions
miscellaneous utility functions
change pretty printer function and add utilities for buffered string construction
append C strings to a buffer
util.c added
just __arc_append_cstring
sketch of pretty printer, and pretty print subroutine for conses
string prettyprinter added
pretty printer function prototype