Add download url, support url and support email

[Schimmelreiter]

Suggestion:

The branding module should be able to return

1. A download URI for the currently running image or None if not specified
2. A support URI (web) for the currently running image or None of not specified
3. A support URI (mailto) for the currently running image or None of not specified

[atvcaptain]

branding is for Hardware not distro Infos or team i think not needed

[Schimmelreiter]

branding is already providing the getImageDistro info, so it's the most logical place where to put such info at.

See https://github.com/oe-alliance/e2openplugin-OpenWebif/commit/5f54ce743b6a8be2726b4657e26fa367a1b6e653 for a reason why we need that info:
The list of images inside the OpenWebif footer is growing and growing. Effectively, we could even add about 20 to 30 distros more to the footer ...

If branding would simply provide a (support) URL to the distro, we could turn the "Distribution:" info inside "Box Info" into a clickable link to that distro (rather than including links to all of them).

I wouldn't know any better place to supply this info than the place which already supplies us with the distro name ...