May 27 - June 03: Prepare/Patch the crossbuild/Multiarch toolchain

The objective of this week was to prepare the toolchain i will use when 
crossbuilding in practice.

In order to understand how the process of create a crossbuild toolchain
works, I created my own toolchain using the upstream sources of
gcc, eglibc and binutils. After some days of work it worked. It was a lot of learning. A big challange was to
change eglibc source to avoid some aspects of the arm architecture that isn't implemented in the eglibc yet.
Also, understand the 3-phase build of gcc and eglibc and the configure parameters of the packages was interesting.

Since we need a Debian based toolchain, I used the armhf-cross-toolchain-base from ubuntu [1] as a start point. Then I 
created a new arm-cross-toolchain that can be installed in Debian. 
The new repository can be found in [2].  The hardest part of the process
was to understand the order in which the sources should be built and update the patchs
for the debian packages. 

The cross-toolchain uses the linux-sources, eglibc, gcc and binutils 
packages. I know that we have other cross toolchains done for debian, but install
then is not easier for begginers and sometimes they don't work anymore with the currently unstable snapshot. 
So, it was easier to understand the process and make my own (not from scratch). 
My intention is to keep the toolchain always updated, clean and easy to install even for begginers. Also, in [3] 
is the pre-build packages from the toolchain and a README file with some explanations on how to install them.

Before updating the armhf-cross-toolchain-base I also installed the thibg's cross-toolchain. I documented all the steps needed
to make it work in [4]. I hope anyone can reproduce it.

The Week 1 finished successfully acording with the schedule. 

I would like to thanks Wookey, Josch and Pehjota for the support they give me. Specially Josch
that spent a lot of time clarifying my ideas. 

References:
[1] https://launchpad.net/ubuntu/+source/armel-cross-toolchain-base
[2] https://github.com/alkmim/arm-cross-toolchain-debian
[3] http://www.lrc.ic.unicamp.br/~alkmim/debian/GSoC2013/crosstoolchain/arm-cross-toolchain-ubuntu/
[4] http://www.lrc.ic.unicamp.br/~alkmim/debian/GSoC2013/crosstoolchain/cross-toolchain-armhf-thibg/README