Updated README.md
Updated index.tpl
Pulled out Blog related code into its own package.
Added config option for blog pagination.
Cleaned up Index and removed some config options.
Another change in post filename format (jekyll format).
Removed stale uses of removed config options.
Yet another blog filename format change.

This should be the final one. The format is "YYYY-MM-DD.title.MARKUP".
Implemented post filename semantics; cleaned up markup/css.
Blog now handles its own routing; first step to permalinks.

* NewBlog now accepts a mux.Router and handles its own routing.
* Permalinks are actually constructed now, but there is no handler
for single post links yet so they just point to main blog.
Moved code under !info.IsDir() check.
Added Blog permalinks and started work on pagination.

XXX: code is working but not very pretty.