- add fixes for CVE-2016-2037, integer overflow and inconsistent
argument passing to printf-like functions, all from upstream.
- add autoconf to checkdepends as autom4te is required to create
built-in tests from templates;
- remove bash from checkdepends (as it is useless without passing
CONFIG_SHELL=/bin/bash to ./configure anyway) and replace the
bash-style sequence expression at tests/symlink-long.at:30 to
resolve test failure;
- disable NLS and make explicit other default ./configure options.
