TDEUI update adaptation for Help Center / TDM minimalist style

1) TDEUI update adaptation for Help Center Pushed in commit 8814b54. Still a couple of things to look at: a) the title of the main help page categories is still in black color and right aligned. I have already rebuilt tdelibs and tdebase, so I expected it to be in the new style. b) the style of pages in the glossary, as Alex already pointed out. 2) Minimalist TDM style Pushed in commit 232cce7, 34d83f4 Good job Alex, thanks for the contribution. Cheers Michele