This commit adds information to the README regarding known issues with some Fortran
compilers and OSHMEM Fortran bindings. This should be added to
cmr=v1.8.2:reviewer=phargrov
usnic: no need to check before calling this function

This function is intentionally always safe to call -- no need for a
double redundant check.
usnic: ensure to have a safe destruction of an opal_list_item_t

It turns out that we ''can'' get to the endpoint destructor with the
endpoint still on the "endpoints needing ACKs" list.  So if it's on
the list, remove it first, and then DESTRUCT the opal_list_item_t.

This prevents an assert() fail in debug builds.  We'd like to let this
soak over the weekend.

cmr=v1.8.2:reviewer=dgoodell