attached a few lines of small changes


* if the time.h fixme is because of the sigevent struct
declaration, then it can go away as posix says
"The tag sigevent shall be declared as naming an incomplete structure type,
the contents of which are described in the <signal.h> header."

actually there is a much stronger statement as well:
"Inclusion of the <time.h> header may make visible all symbols from the
<signal.h> header."


* __syscall_ret: declaration should be consistent with the function
definition (argument is signed long)

i think one of the (unsigned long) casts is unnecessary due to conversion
rules but it probably makes things more clear


* sbrk: changed prototype here as well to be consistent with the standard

actually semantically ptrdiff_t is better (sbrk does p+arg, not p=arg)
but the standard uses intptr_t

this change should not hurt as sbrk should not be used anyway..
(i guess there is no architecture where intptr_t != ptrdiff_t)


* __asctime: use new crash (i assume the *0=0 crash is deprecated now)


* setpgid: pid_t return type is wrong (return value is an error code)