* inf-child.c (inf_child_follow_fork) New parameter

	* inf-child.c (inf_child_follow_fork) New parameter
	detach_fork.
	* inf-ptrace.c (inf_ptrace_follow_fork): Likewise.
	* inf-ttrace.c (inf_ttrace_follow_fork): Likewise.
	* inferior.h (detach_fork): Remove.
	* infrun.c (detach_fork): Adjust comment and make it
	static.
	(follow_fork): Pass detach_fork parameter to
	target_follow_fork.
	* linux-nat.c (linux_child_follow_fork): New parameter
	detach_fork.
	* target.c (target_follow_fork): New parameter detach_fork.
	Pass detach_fork as parameter and print its value.
	* target.h (struct target_ops) <to_follow_fork>: New int
	parameter.
	(target_follow_fork): New parameter detach_fork.