provide doxygen based documentation online

[mfrey]

Hi,

as pointed out by @cgundogan in PR #222 it would be awesome if we could have the (doxygen generated) documentation online at a central point, either something like http://doc.ccn-lite.net/ or http://ccnlite.github.io (see also GitHubs documentation on project pages). I think the most important requirement would be to have the possibility to update the documentation website on demand.

@cmarxer @blacksheeep what do you think?

Best,
Michael