Update TODO with assigned task

So that everybody can know which tasks are already in progress.
Merge branch 'master' of github.com:serge-sans-paille/pythran
Make Python and Cxx backend denser

Remove additional newlines that were disgraceful in doc test strings.
Code cleaning

Use generic_visit whenever possible.
Improve Methods Normalization

* Now allows to call methods as a function, e.g. list.append(l,1)
* More testing too