Blog and index pages partly working

Index page does not list post titles, but the links are correct.
Fixed hard-coded paths in router

The hard-coded paths in skinny-router were not replaced with variables
in commit 2e97755.
Fixed router paths

Removed extra slash after skinny-blog-dir in format strings, and
removed unused `favicon-sender'.
Rewrote blog post renderer.

* Use creole-html and esxml instead of creole-wiki.
* Removed headers and footers.
Changed blog post URLs

Blog post URLs are now the post file name without the ".creole"
extension.  (The actual files still have the extension.)
Partial blog Atom feed

Implemented generating Atom feed from output of `skinny/list-posts',
but with some missing values; need to...

* add variable for blog title,
* determine absolute feed URL,
* get post title and timestamp,
* and generate post UUID.
Clarify skinny/list-posts docstring

Mention that output is list of post file-names.
Corrected <entry> <link> URLs in blog feed.
Added blog-name variable

Added Customize option `skinny-blog-name'.
Get post metadata

Skinny now gets post metadata -- title, author, timestamp, and UUID --
from a corresponding .el file.
Added missing `save-match-data'
Fixed clobbering of match-data

insert-file-contents clobbers match-data, so surround all invocations
with save-match-data.
Corrected blog css path

Fixed code for computing relative css URL for blog post <link>s.
Added <post> and <header>

Blog posts are now in a <post> element, and now have a <header> with
the title and timestamp.
Corrected element name

There is no such <post> element; I meant to use <article>.
Added language-code variable

Added variable `skinny-lang', which is used as the value of the lang
attribute in XML and HTML.
Allow multiple blog CSS files

Changed skinny-blog-css-file-name to skinny-blog-css-file-names, a
list of CSS file names.
Added class to <article>

Added skinny-blog-article-class variable to specify class attribute
for <article> element.
Added site-wide author variable

Added `skinny-blog-author' variable to specify the author site-wide,
rather than for each post, although the author field of a post will
still be used if present.
Rearranged functions

Rearranged order of defuns in skinny.el