clarify that posix does not match what anyerror does.
add test for anyerror (Pavel Raiskup)
paulo.cesar.pereira.de.andrade: prevent forking if the end of a pipeline is
a builtin: cat /etc/passwd | echo, fg, fg
PR/377: Angelo Bonet: Fix source memory leak
Add missing backquote.
Look at all host files that match the standard ones as a prefix.
Add an "editors" variables to be set to the list of commands that we
consider editors that we want foregrounded with run-fg-editor.
Add noimplicithome.
rename noimplicitcd to cdtohome
Fix compile warnings

GNU libc 2.20 deprecates _BSD_SOURCE & _SVID_SOURCE in favour of
_DEFAULT_SOURCE, you get the following warnings:

	clang -c -g -O2 -I. -I. -D_PATH_TCSHELL='"/usr/local/bin/tcsh"'    sh.dir.c
	In file included from sh.dir.c:33:
	In file included from ./sh.h:39:
	In file included from /usr/include/signal.h:28:
	/usr/include/features.h:148:3: warning: "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE" [-W#warnings]
	# warning "_BSD_SOURCE and _SVID_SOURCE are deprecated, use _DEFAULT_SOURCE"
	  ^
	1 warning generated.

This adds _DEFAULT_SOURCE to the Linux config.h, since GNU libc only runs on
Linux.

Also see:
- http://en.wikipedia.org/wiki/GNU_C_Library#Supported_hardware_and_kernels
- http://lwn.net/Articles/589730/
- http://lists.nongnu.org/archive/html/chicken-hackers/2014-10/msg00106.html