configure: fix --with-foo=/path/to/foo

When a required tool is specified with --with-foo, store the variable
in the list.
(transplanted from 1d43b65599a4b869d83d4db67b9715b1298d74f7)

configure: force using the C locale to check messages

configure: fix --with-foo=/path/to/foo

When a required tool is specified with --with-foo, store the variable
in the list.

eglibc: add support for user provided option groups

Signed-off-by: Arnaud Vrac <avrac@freebox.fr>

samples: fix the avr32-unknown-none sample

Bizarely enough, binutils-2.18 fails to build when CONFIG_SHELL is set
to /bin/bash (although it has code to recognise bash and act accordingly).

Waht is really strange is that it does build when CONFIG_SHELL is set
to /bin/sh, *although* /bin/sh is a symlink to /bin/bash. WTF?!?!
(transplanted from 56bba7d4fc8924d276b71134b7f1ef57bed57f52)

samples: fix the avr32-unknown-none sample

Bizarely enough, binutils-2.18 fails to build when CONFIG_SHELL is set
to /bin/bash (although it has code to recognise bash and act accordingly).

Waht is really strange is that it does build when CONFIG_SHELL is set
to /bin/sh, *although* /bin/sh is a symlink to /bin/bash. WTF?!?!

Tagging release 1.5.0

1.5: update version to 1.5.0

1.5: create maintenance branch for the 1.5 series

samples: update