[Dillo-dev] [patch]: modernize configure.in's initialization and configuration

Now that I run it instead of just reading the documentation (reminds me of that one Knuth line), I get some configure.in:9: warning: AC_ARG_PROGRAM was called before AC_CANONICAL_TARGET ./../lib/autoconf/general.m4:1843: AC_CANONICAL_SYSTEM is expanded from... configure.in:9: the top level