First commit of the i18n feature.

Most of the strings were exported in lang/en-GB.php.
i18n - lang en-GB and fr-FR

eLabFTW is now localized ! Next languages will probably be : spanish and
brazilian.
Bootstrap.

Add bootstrap via bower.
s/status/statut in FR.
change css of alerts (wip)
put columns on search
register page is now with grid layout
ucp is now bootstraped
bring back the good colors for alert messages
editXP is now bootstrapped
put images 5px up so they are aligned

and some other bugfixes
better ucp page (add block class to label)
fix body color for issue #52
(dirty) fix for issue #54

and also fix for delete file lang not loaded.
in fact we don't want to reload the whole page, because you'll lose the

things you wrote. Issue #54
add lang in config to install
add lang to elab install.sql
add warning alert
nothing serious
add lang to timestamp
add back textalign
use badge class for templates listing
add margin to badges