build: add Automake-like silent/verbose macros for "ln -s ..." operations

Also, since I put some of the macros for these silent/verbose rules up
in the top-level Makefile.man-page-rules file, I renamed it to
Makefile.ompi-rules.

I've had this sitting around for a while; now seems like as good a
time as any to commit it.
osc/base: fix one more case in ompi_osc_base_sndrcv_op

This fixes more issues identified by armci. More issues still remain and fixes are
coming for those as well.

cmr=v1.8:reviewer=jsquyres
coll/ml: more fixes

There were a couple of issues with the memory leak fixes and several more verbose
issues. This fixes those issues.

cmr=v1.8.1:ticket=#4473
Sync NEWS with v1.8 branch