simplify installation rules, using new Automake

simplify installation rules, using new Automake

This relies on development Automake to provide multi-file
installation, and avoids relying on undocumented Automake
interfaces.  It also removes special-casing for `['.
* configure.ac (AM_INIT_AUTOMAKE): Depend on 1.10a.
(CROSS_COMPILING): New Automake conditional.
* src/Makefile.am (install-exec-am, filtered_PROGS)
(d_bindir, cu-install-binPROGRAMS): Remove.
(INSTALL_PROGRAM) [!CROSS_COMPILING]: Set to `./ginstall'.