update config.rpath from gettext 0.21.1. previous copy was 17 years old
rename config/ to system/ to reduce tab completion conflict with configure.
fix installation of tcsh.man when building out of source
use build-aux/ as the autoconf aux dir, so config.guess, config.rpath, config.sub, and install-sh can be moved moved to ./build-aux/, to reduce tab completion conflict with configure.
manually move config.rpath (etc) from ./ to build-aux/ (because autopoint won't run nor do we want it to - see commit e3440c4), and then run autoreconf to update configure and aclocal.m4.
Various improvements:
config/tosystem/to reduce tab completion conflict withconfigure.build-aux/as the autoconf aux dir, soconfig.guess,config.rpath,config.sub, andinstall-shcan be moved moved to ./build-aux/, to reduce tab completion conflict withconfigure.config.rpath(etc) from./tobuild-aux/(becauseautopointwon't run nor do we want it to - see commit e3440c4), and then runautoreconfto updateconfigureandaclocal.m4.