opal_search_libs: correctly AC_DEFINE results of search

1. It is not sufficient to put the result of m4_toupper() in a
variable and use that variable as the variable name in
AC_DEFINE_UNQUOTED.  Instead, just use m4_toupper() directly in
AC_DEFINE_UNQUOTED.  Also, save the result value in a "permanent"
variable that isn't erased, just in case autoconf decides to be lazy
about instantiating the body AC_DEFINE_UNQUOTED and move it later
(this is probably overkill :-) ).
1. Use the OMPI Way of always defining macros (to 0 or 1).  Then also
slightly change the logic in util/basename.c to just check
OPAL_HAVE_DIRNAME (because it will always be defined).

Refs #4894
plm_rsh_module.c: output to the framework output

Trivial fix from r32686: don't output to stream 0, but rather to
orte_plm_base_framework.framework_output (this is the way it was
before r32686).  In reality, this is going to end up being stream 0,
anyway, but we might as well be pedantically correct...

Refs #4897.