Removes API Programming Guide from index.html links

Updates /trunk/ index.html to point to image guide current URL
Removes "Documentation" from Tempest Test Suite link text
Does not place Config Ref trunk on the main index.html since
it is on the /trunk/index.html.

Change-Id: I33901235ff0170130e33089830ed359ae2bfa665
Use a more generic URL for ubuntu image download

Change-Id: Ie04b949f84fbe6cd7ab06248597597ce3db9f9c1
Merge "Use a more generic URL for ubuntu image download"
Merge "Removes API Programming Guide from index.html links"