+ Addition of function prototypes.
+ Change function definitions to ANSI C style.
+ Initial support for CMake
+ Added support for sys_tmpdir for better portability.
Drop dependency on <ansi.h> in modules+headers; assume that compiler
knows ANSI C89.
Add missing dependency from print to string; #include <ack_string.h>.
Because <print.h> had commented out the declarations of sys_lock() and
sys_unlock(), I now stop building lock.c and unlock.c.