gnu: Add missing patch for mcron.

* gnu/packages/patches/mcron-install.patch: New file.
* Makefile.am (dist_patch_DATA): Add it.

Makefile.am

@@ -196,6 +196,7 @@ dist_patch_DATA =						\
   gnu/packages/patches/m4-readlink-EINVAL.patch			\
   gnu/packages/patches/m4-s_isdir.patch				\
   gnu/packages/patches/make-impure-dirs.patch			\
+  gnu/packages/patches/mcron-install.patch			\
   gnu/packages/patches/perl-no-sys-dirs.patch			\
   gnu/packages/patches/procps-make-3.82.patch			\
   gnu/packages/patches/readline-link-ncurses.patch		\

gnu/packages/patches/mcron-install.patch

@@ -0,0 +1,22 @@
+This patch allows us to install the Vixie-compatible binaries as
+non-root without creating /var/run, etc.
+
+--- mcron-1.0.6/makefile.in	2010-06-19 20:44:17.000000000 +0200
++++ mcron-1.0.6/makefile.in	2010-07-04 16:16:25.000000000 +0200
+@@ -1004,15 +1004,11 @@ mcron.c : main.scm crontab.scm makefile.
+ 	@rm -f mcron.escaped.scm > /dev/null 2>&1
+ 
+ install-exec-hook:
+-	@if [ "x@NO_VIXIE_CLOBBER@" != "xyes"   -a   "`id -u`" -eq "0" ]; then \
++	@if [ "x@NO_VIXIE_CLOBBER@" != "xyes" ]; then \
+        rm -f $(fpp)cron$(EXEEXT) > /dev/null 2>&1; \
+        $(INSTALL) --mode='u=rwx' mcron$(EXEEXT) $(fpp)cron$(EXEEXT); \
+        rm -f $(fpp)crontab$(EXEEXT) > /dev/null 2>&1; \
+        $(INSTALL) --mode='u=rwxs,og=rx' mcron$(EXEEXT) $(fpp)crontab$(EXEEXT); \
+-       $(INSTALL) -d --mode='u=rwx' $(DESTDIR)/var/cron; \
+-       $(INSTALL) -d --mode='u=rwx,og=rx' $(DESTDIR)/var/run; \
+-       $(INSTALL) -d --mode='u=rwx,og=rx' $(DESTDIR)@GUILE_SITE@; \
+-       $(INSTALL) -d --mode='u=rwx,og=rx' $(DESTDIR)@GUILE_SITE@/mcron; \
+     elif [ "x@NO_VIXIE_CLOBBER@" = "xyes" ]; then \
+        echo "Not installing Vixie-style programs"; \
+     else \