config: prepare for build-system backend

When acting as a backend for a build-system, we should not build
any application that runs on the target, that is:
- no native gdb
- no companion libraries
- no binutils libraries
- no debug tools (save for gdbserver)
- ...

Here, we simply prepare the (hidden) config option that will detect
that we are acting as a back-end.

Update doc accordingly.

samples: fix samples

kernel/linux: add latest versions 2.6.32.10 and 2.6.33.1

debug/gdb: fix building the native tic

The native 'tic' will _always_ be run on the build
machine, so no need to handle canadian/native/...

Reported by: Trevor Woerner
http://sourceware.org/ml/crossgcc/2010-03/msg00055.html
(transplanted from 26e89d367ea11660fd3a0bf0bcad8763e4fa21cf)

debug/gdb: fix building the native tic

The native 'tic' will _always_ be run on the build
machine, so no need to handle canadian/native/...

Reported by: Trevor Woerner
http://sourceware.org/ml/crossgcc/2010-03/msg00055.html

scripts: fix the release script to use the C locale

Force use of the C locale to ensure messages are recognised by the script.

1.6: update version to 1.6.1+hg

Tagging release 1.6.1

1.6: update version to 1.6.1

scripts: enhance and fix the release script