update admin.

- put “Theme Options” page under “Appearances”.
- remove extensible config for ore Admin pages.
add pagination.
add breadcrumbs.
fix header getimagesize error.
add custom background support.
update "byline" function.
add "category" and "tag" list to posts.
remove unnecessary code.
remove duplication in "get_directories".
change "story" to "post".
update content and sidebar css.
move css from "full-size.css" to main style.
fix background color for site wrapper.
eliminate image width overflow.
update css.