Cleaning extra whitespaces

Some files have been edited in ActiveState Komodo or other editors
without taking care to ensure line returns don't add extra spaces.

This change cleans these whitespaces so we've a sane code base more
comfortable to edit, without seeing extra whitespaces 'blinking' in
nano, git diff or code review systems.

Command used:
ack --print0 -l '[ \t]+$' | xargs -0 -n1 perl -pi -e 's/ +$//'

A follow-up commit, after code conventions clarification, to hunt
tabulations / whitespaces errors is welcome.