Update header-entete.php

rewrote the header-entete.php file to be more readable. Fixed several if statements and pathing issues.
Update header-entete.php

changed the paths from /build to /dist
Update header-entete.php

changed paths for php includes to point to the /demos-php folder instead of /dist folder.
Merge pull request #28 from upsonp/patch-3

Update header-entete.php