Started some work on the FAQ. Split into different sections and ported some of...

Started some work on the FAQ. Split into different sections and ported some of the old faq from wikisyntax into ReST.\nNo real plan behind the split, just adding sections that seem useful to have as I go through the old FAQ.

git-svn-id: http://www.varnish-cache.org/svn/trunk/varnish-cache@4784 d4fa192b-c00b-0410-8231-f00ffab90ce4