Now that we're using AM_SILENT_RULES this needs to be set so we can
see what's going on in our build logs.

Autogenerated bits of the code warn when building which would
otherwise break the build.

FS-6375 adding LTCFLAGS makes configure choose the proper pre post deps on both 32bit and 64bit just work out of the box

FS-6292 additional define to avoid on NetBSD, If someone wants to get this workign please submit patches

These haven't been touched in years; they can't possibly still be
applicable.

...by separating out CPPFLAGS and CXXFLAGS.

This doesn't seem needed, and the empty include was breaking the
build.

CPPFLAGS should contain -I and -D flags.

This also has the effect of fixing the build of this module.

...including one syntax error and an underspecified cast.