Beautify the progress bar.

Fix handling of downloader output: they are now correctly logged using the internal log facility.

Huge fixes to glibc build, so that we can build at least (and at last):
- use ports addon even when installing headers,
- use optimisation (-O) when installing headers, to avoid unnecessary warnings (thanks Robert P. J. DAY for pointing this out!),
- lowest kernel version to use is only X.Y.Z, not X.Y.Z.T,
- a bit of preparations for NPTL (RSN I hope),
- fix fixing the linker scripts (changing the backup file is kind of useless and stupid);

Shut uClibc finish step: there really is nothing to do;

Add a patch for glibc-2.3.6 weak aliases handling on some archs (ARM and ALPHA at least);

Did not catch the make errors: fixed the pattern matching in scripts/functions;

Introduce a new log level, ALL:
- send components' build messages there,
- DEBUG log level is destined only for crosstool-NG debug messages,
- migrate sub-actions to use appropriate log levels;

Update the armeb-unknown-linux-gnu sample:
- it builds!
- uses gcc-4.0.4 and glibc-2.3.6,
- updated to latest config options set.

Inform that a component is already extracted.

Print the elapsed time alongside with the progress bar, such as below:
[02:27] \

Cosmetics: newline at end of file, ports are now a separate option.

Print the major components and their version when calling "make help".

Bah. Be silent when there is nothing to do: glibc has no config (file) to check.

Remove the incomplete i686-unknown-linux-uclibc sample.

Update the i586-geode-linux-uclibc sample.