* procfs.c (procfs_wait): Fix argument name to match 4 Jan changes.

	* procfs.c (procfs_wait): Fix argument name to match 4 Jan changes.
	* Move target_signal_from_host, target_signal_to_host, and
	store_waitstatus from inftarg.c to target.c.  procfs needs them.
	* target.c: Include "wait.h" and <signal.h>.
	* target.h, infrun.c (proceed), proceed callers: Pass new code
	TARGET_SIGNAL_DEFAULT instead of -1.  This avoids problems with
	enums being treated as unsigned and is cleaner.
	* infrun.c (signals_info): Don't print TARGET_SIGNAL_DEFAULT or
	TARGET_SIGNAL_0.
	* infcmd.c (signal_command), infrun.c (signals_info):
	Don't allow user to specify numeric equivalent of
	TARGET_SIGNAL_DEFAULT.