MFH: r499037

Fix build when hamlib is installed.

Put /usr/local/include at end of AM_CPPFLAGS instead of at beginning,
ensures the included header files are used.

Link included hamlib using ${libdir}/libhamlib.a rather than -lhamlib to
ensure the included static hamlib is used instead of a dynamic one in the
library path.

Approved by: ports-secteam (miwi)