* cygwin.din: Export getpriority and setpriority.

* fork.cc (fork_parent): Copy parent's nice value into child.
	* spawn.cc (spawn_guts): Ditto.
	* miscfuncs.cc (winprio_to_nice): New function.
	(nice_to_winprio): Ditto.
	* pinfo.cc (pinfo_init): If parent is not a Cygwin process, set
	default nice value according to current Win32 priority class.
	* pinfo.h (class _pinfo): Add nice member.
	* syscalls.cc (setpriority): New function, only implementing
	PRIO_PROCESS for now.
	(getpriority): Ditto.
	(nice): Just call setpriority.
	* wincap.h (wincaps::has_extended_priority_class): New element.
	* wincap.cc: Implement above element throughout.
	* winsup.h: Add prototypes for winprio_to_nice and nice_to_winprio.
	* include/limits.h (NZERO): New define.
	* include/cygwin/types.h (id_t): New datatype.
	* include/cygwin/version.h: Bump API minor version.
	* include/sys/resource.h: Add PRIO_XXX defines and prototypes for
	getpriority and setpriority.

winsup/cygwin/pinfo.cc

@@ -98,6 +98,8 @@ pinfo_init (char **envp, int envc)
       myself->uid = ILLEGAL_UID;
       myself->gid = UNKNOWN_GID;
       environ_init (NULL, 0);	/* call after myself has been set up */
+      myself->nice = winprio_to_nice (GetPriorityClass (hMainProc));
+      debug_printf ("Set nice to %d", myself->nice);
     }
 
   debug_printf ("pid %d, pgid %d", myself->pid, myself->pgid);