Ship bash with Core Update 86 again

It seems that some systems installed some pre-versions
of the distribution which came with an outdated version
of bash. Since this update uses some scripts that use
bash-4-isms, we ship the shell once again.

An other reason is that there have been security fixes
in the shell which should be fixed on all systems.

diff --git a/config/rootfiles/core/86/filelists/bash b/config/rootfiles/core/86/filelists/bash
new file mode 120000 (symlink)
index 0000000..de970cb
--- /dev/null
+++ b/config/rootfiles/core/86/filelists/bash
@@ -0,0 +1 @@
+../../../common/bash
\ No newline at end of file