seq -0.1 0.1 2: print final number when locale's decimal point is ","

seq -0.1 0.1 2: print final number when locale's decimal point is ","

* src/seq.c (print_numbers): Use strtold, not c_strtold to convert
from just-formatted-using-asprintf string back to double, since
asprintf may have used something other than "." as the decimal point.
Reported by lsof@nodata.co.uk as <http://bugzilla.redhat.com/463556>.
Thanks to Ondřej Vašík for discovering that the bug was locale-related.

    $ LC_ALL=cs_CZ.UTF-8 seq -0.1 0.1 2|grep 2.0
    [Exit 1]
    $ seq -0.1 0.1 2|grep 2.0
    2.0

* tests/check.mk (TESTS_ENVIRONMENT): Add LOCALE_FR_UTF8, for...
* tests/misc/seq [locale-dec-pt]: New test for the above.
* NEWS (bug fix): Mention it.