Our checks and the ones of libevent are somewhat flawed.
If adding multiple "-framework" to CXXFLAGS or CFLAGS, we strip
the keyword from the command-line, not good.
libevent however assumes plain gcc without testing properly
that the compiler supports -Wno-deprecated-declarations.
Define OPAL_MAXHOSTNAMELEN to be either:
(MAXHOSTNAMELEN + 1) or
(limits.h:HOST_NAME_MAX + 1) or
(255 + 1)
For pmix code, define above using PMIX_MAXHOSTNAMELEN.
Fixup opal layer to use the new max.
Signed-off-by: Karol Mroz <mroz.karol@gmail.com>