Add mutt-sidebar-patch for mutt 1.5.22

When mutt was bumped to 1.5.22 the sidebar patched was removed. I repaired the patch using the latest patch in FreeBSD [1][2] and updated the Formula accordingly.

[1] http://www.freebsd.org/cgi/query-pr.cgi?pr=183251
[2] http://svnweb.freebsd.org/ports/head/mail/mutt/files/extra-patch-sidebar?view=log

Thanks!

D.