debug/gdb: remove insight

Insight seems to be very slow to follow up on mainstreram gdb.
Latest snapshots are more than 6 months old.

Moreover, I don't have time to maintain insight support in crosstool-NG;
and, because I don't use it, I am unable to find any breakage.

debug/gdb: reorder options in the menuconfig

debug/gdb: allow static build with complibs

It is now possible to built static versions of the companion libraries,
so we can now build a static cross-gdb using the complibs.

scripts: don't print the build system guess warning

complibs/gmp: mark 5.0.1 as being experimental

MPFR can't cope with GMP > 4.x.y so hide it behind EXPERIMENTAL
until we fix MPFR

samples: add Blackfin sample

Add basic support for the Blackfin architecture

For uClibc, the name of the Blackfin architecture is 'bfin'. Actually,
the naming of the architecture is quite messy: for toolchain tuples
and uClibc, it's bfin, but for the kernel, it's blackfin. We've
arbitraly choosen to name it "blackfin" in Crosstool-NG.

Add Blackfin-related uClibc patch to fix a build failure related to
fork() being used in unistd/daemon.c.

Yann E. MORIN:
Apply the patch to the kernel/linux build script to use 'linux'
in the noMMU tuples. See:
http://sourceware.org/ml/crossgcc/2010-04/msg00010.html

scripts/functions: log the test strings

scripts/functions: compress with gzip level 3, as stated in the documentation

Thanks to Bruno Tarquini <btarquini@gmail.com> for the report.

scripts/functions: add a save/restore handler

Saving and restoring the steps requires saving/restoring multiple
directories. Depending on the configuration, some may not exist.

Add a wrapper that checks before creating/extracting the tarballs.