$ cd .. # project/git/tarball root
$ autotools/bootstrap

will create "configure.gnu", which should behave much like a normal autotools
"configure" script

TODO: non-POSIX systems.
- TEST: configure.ac needs to detect condition (e.g. from qucs)
- plugins need to be linked to libgnucap (apps.am, cf. apps/Make2.mingw32 +31)
- (WORKAROUND: "make APPS_LIBADD=../lib/libgnucap.la")

TODO: cross compile
- somehing like ./configure --build i686-pc-linux-gnu --host i586-mingw32msvc
- need to build modelgen twice. how?

cross compilation
- Supported by autotools [1]
- Select toolchain (Debian package? or [2]?). untested
- Need a compiler on target platform. Which one?
- TODO: deal with modelgen.
  WORKAROND: "make GNUCAP_MODELGEN=gnucap-modelgen"

# gdb use in autotools
libtool --mode=execute gdb --args ../bd/main/gnucap.real -b d_logic_tr_db1.ckt

[1] https://www.gnu.org/software/automake/manual/html_node/Cross_002dCompilation.html
[2] mxe.cc
