Added translation-check.wml

[Javier Fdz-Sanguino Pen~a <jfs@ieeesb.etsit.upm.es>]

	I have added translation-check to the templates in the english/
subdir so it can be used by all translators. I will notify of further
modifications to make the change from

<!-- translation X.X ->

to 

#use wml::debian::translation-check translation="X.X"

	smoother.

	The advantage: have the same functionality we have but add more
content information to the users so they are aware (a prominent notification is
printed in the page, maybe we could use a javascript screen) if the
document they are reading (which is the one they receive because of content
negotiation) is not showing the most current information and forward them
to the english source.

	Regards

	Javi