Prepare to release crosstool-ng-0.0.4.

scripts/showSamples.sh:
- revert sample dumping to not show the components versions;

docs/overview.txt:
- reorder docs/overview.txt so that configuring comes before running,
- tell about regtest;

Makefile:
config/global.in:
- point to docs/overview.txt for the list of steps;

Add intermediate mesages when building regtests.
Distclean the repository after each sample during regtests.

Add the "regtest" make target: call "make regtest", and all samples wil be built, and a tarball made for each of them. First sample to fail causes the test to stop.

scripts/functions is responsible for initiating the log file.
Users of the log facility are in charge to use, move, delete this log file, now.

Fix printing components' file names.

Answer default values when doing a defoldconfig.

When doing a silent old config, don't check if stdin was redirected. ct-ng doesn't use this feature, and even better yet, it makes explicit use of redirecting both stdin and stdout at aome moments.

Add a function to print each component's filename: this eases building the tarball of the generated toolchain.
Hard-link the libfloat tarball instead of soft-link: this also eases building the afore-mentioned tarball.

When searching a matching extension for a file, also check for the empty extension.