Use .RelPermalink instead of .Permalink in theme.

.Permalink always prepends the config .baseurl. But that is not
required for internal links in HTML. Causes issues when site is
generated using hugo without using the "server" option and trying to
serve site at any location other than "base url".

Only use .Permalink in meta things like site map, RSS/Atom feeds, html
meta tags, etc..
Use site.Params.Title and .site.Params.TagLine

Stadardize access to all custom parameters using the .site.Params
variable.
<title> and description <meta>