Country & language codes for Danish installation
Expanded the external-link-script with a css-class
Change to upload scripts requested by Clement

I'm correcting the epidb upload script for our country and I figured that the Q15 (intake) not collected in our country.
It is not possible to provide a NULL value for Q15_*. Can you change the definition of the columns to accept NULL value for non mandatory (Q15 at least) questions ?
Merge remote branch 'origin/master'
revamped cohorts script to allow for general set of control/measurement variables
Merge branch 'master' into british-changes