In particular, fix the following errors and warnings:
configure.ac:2: warning: AM_INIT_AUTOMAKE: two- and three-arguments forms are
deprecated. For more info, see:
configure.ac:2: http://www.gnu.org/software/automake/manual/automake.html
#Modernize-AM_005fINIT_005fAUTOMAKE-invocation
Makefile.am:21: error: linker flags such as '-shared' belong in
'gkhdplop_so_LDFLAGS'
./configure: line 2910: syntax error near unexpected token `build_old_libs,'
./configure: line 2910: ` _LT_DECL(build_old_libs, enable_static, 0,'
./configure: line 2908: syntax error near unexpected token
`build_libtool_libs,'
./configure: line 2908: ` _LT_DECL(build_libtool_libs, enable_shared, 0,
https://sources.debian.net/src/wmhdplop/0.9.9-5/debian/patches/
modernize_autotools.patch/