docs: get rid of any reference to the now long-gone svn repository

docs: move the "contributing" section to overview.txt

docs: configure no longer accepts --with-contrib

It's been a while that configure does not recognise --with-contrib.
Applying contibutions is to be done manually, using patch.

configure: force using the C locale to check messages
(transplanted from 2f44fac6b5143f7b14f5367209c9df9b1102298e)

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?!?!