* src/fio.h: Added macros to deal with signal handling. These will call into the POSIX package if it is present, but are null if it is not. * src/select.cxx: Renamed original select() to cyg_pselect() and added select() and pselect() routine from POSIX-200X to call it. Reorganized code a little and added calls to macros to deal with signal delivery and detection. * cdl/fileio.cdl: * tests/pselect.c: New test added to verify the signal masking and delivery behaviour of pselect(). * tests/select.c: Fixed up some printfs to make it a little tidier.