make landing pages https-clean

Because several Ad Words Landing pages contain forms where the users submit their email or even a complete registration, it seems preferrable to serve them over https (so that they realize that the transmission secure).

For this to work, no request using the http protocol should be made for any resource employed by the page (scripts, styles, images...). The default scripts, images, and styles are all automatically switching to https if this protocol is detected.

Some AdWordsPages, however, should be correct: for example SearchEmailJoinAdMath contains an ad that triggers an http call, it also contains an html header which is wrong, and a call to some extra javascript and css.