tools wrapper: introduce the silent WRAPPER_NEEDED config option

Add the WRAPPER_NEEDED silent config option, that can be selected by
components that require it (companion libs so far).
Rely on this config option when deciding to install the wrapper,
instead of checking GMP/MPFR or PPL/CLoog/MPC.

Merge the C wrapper.

config: choose whether to use the shell or the C wrapper

Offer a config choice on whether to isntall the script wrapper, or
the compiled C wrapper. Update docs/overview.txt accordingly.

tool wrapper: add initial wrapper coded in C

Add an initial wrapper:
- find the realpath of the tool being called
- add the '.' in front of the tool name
- add the '/lib' dir to the base dir of the tool
- set and export LD_LIBRARY_PATH
- execve the real tool

overview: fix table of content, fix the hacker's way

table of content: add missing entry
the hacker's way: no need to "make install"

README: fix some space alignment

duma: fix downloading by forcing extension to .tar.gz

Downoading a non-existing file from sourceforge gives you a "200 OK"
and an index.html. As we try to retrieve a .tar.bz2 first, and duma
is bundled in a .tar.gz, we won't get appropriate content, so
just force the extension to avoid the problem.

Thanks to Ingmar Schraub <is@eseco.de> for pointing out the issue.

x86_64: is a MMU-aware arch, so select ARCH_USE_MMU

duma: fix version string.

DUMA uses '_' not '.' for major/minor/sub separation.

glibc: fix build error caused by incorrect variable assignment

During the conversion to using bash arrays, the glibc build script
was improperly converted, and contains an incorrect variable
assignment to the config_options array.

Merge the bash_array branch.

For every components where it makes sense, use bash arrays (instead
of a string with space-separated values) to store the options pased
to ./configure.

Allow setting --enable-cxx-flags on gcc ./configure

Some setups require one to pass extra CXX flags at the time of ./configure.
Make it easy.

Use bash arrays to store binutils config options

Make glibc's extra_config an array containing ./configure options

Change extra_config from a string to a array of options.

Make gdb's extra_config an array containing ./configure options

Change extra_config from a string to a array of options.

Make dmalloc's extra_config an array containing ./configure options

Change extra_config from a string to a array of options.

Make gcc's extra_config an array containing ./configure options

Change extra_config from a string to a array of options.

Make eglibc's extra_config an array containing ./configure options

Change extra_config from a string to a array of options.

configure: check for bash-3.1 or above

This is required to use the array variables that came with bash-3.1.

[libc-eglibc] Rewrite part of the code

Rewrite part of the code to better match the rest.
Most notably, rewrite handling of:
if [ ... ] && [ ... ]
to:
if [ ... -a ... ]

This has the positive side effect of calling "[" only once, although
"[" is probably a shell built-in.

[libc-eglibc] Fix testing for existing files

To test for existing files, use "[ -f blabla ]", not "[ -a blabla ]"
Checking for a file exsitence with "-a" is a bashism.
Althoug we _are_ using bash, it's disturbing as it can be misread as
the 'and' operator. Fix by using "-f".

samples: add eglibc-based toolchain for MIPS.

config: add Linux kernel 2.6.30.5

config: update Linux kernel long-term stable to 2.6.27.31.

Merge the AVR32 support branch to the default branch.

Removed debug line

Fix libc config

Misc AVR32 cleanups.

Changed copyright

Update README on how to send proper patches

Add a few lines of explanations on how to correctly setup
and use Mercurial to send proper patches.