Rename module 'unused-parameter' to 'snippet/unused-parameter'.

* modules/snippet/unused-parameter: Renamed from
modules/unused-parameter.
(Files, Makefile.am): Update.
* build-aux/snippet/unused-parameter.h: Renamed from
build-aux/unused-parameter.h.
* modules/selinux-h (Depends-on): Update.
* modules/unistr/base (Depends-on): Update.
* MODULES.html.sh (Core language properties): Update.

modules/snippet/unused-parameter

@@ -0,0 +1,40 @@
+Description:
+A C macro for declaring that specific function parameters are not used.
+
+Applicability:
+all
+
+Files:
+build-aux/snippet/unused-parameter.h
+
+Depends-on:
+
+configure.ac:
+
+Makefile.am:
+# The BUILT_SOURCES created by this Makefile snippet are not used via #include
+# statements but through direct file reference. Therefore this snippet must be
+# present in all Makefile.am that need it. This is ensured by the applicability
+# 'all' defined above.
+
+BUILT_SOURCES += unused-parameter.h
+# The unused-parameter.h that gets inserted into generated .h files is the same
+# as build-aux/snippet/unused-parameter.h, except that it has the copyright
+# header cut off.
+unused-parameter.h: $(top_srcdir)/build-aux/snippet/unused-parameter.h
+	$(AM_V_GEN)rm -f $@-t $@ && \
+	sed -n -e '/GL_UNUSED_PARAMETER/,$$p' \
+	  < $(top_srcdir)/build-aux/snippet/unused-parameter.h \
+	  > $@-t && \
+	mv $@-t $@
+MOSTLYCLEANFILES += unused-parameter.h unused-parameter.h-t
+
+UNUSED_PARAMETER_H=unused-parameter.h
+
+Include:
+
+License:
+LGPLv2+
+
+Maintainer:
+Bruno Haible