Made some adjustments trying to put the logo in place.
Added a themePreview image
just copy an image file per user, to "/upload" with
id as its name

i.e: copy myImage.png -> upload/978c60ff-b1e0-0342-c6eb-509b38c71013

The theme will display user's photo, instead of gearwheel

	modified:   css/style.css
	modified:   images/themePreview.png
	modified:   tpls/_globalLinks.tpl
	modified:   tpls/header.tpl
made some adjustment trying to locate the logo inside the bar
	modified:   tpls/header.tpl
Merge pull request #1 from Danisan/master

Merge last changes