Add a couple of NEWS bullets in prep for 1.7.5 release

cmr=v1.7.5:reviewer=ompi-gk1.7
Per discussion with Josh Ladd, remove this dead man page code.

The code is not used anywhere, so let's remove it until there are some
man pages to install.

Submitted by Jeff Squyres, reviewed by Josh Ladd.

cmr=v1.7.5:reviewer=ompi-gk1.7:subject=remove oshmem dead man page code