Azoth SS: correclty set base URL for themes.

Allows to keep styles and even images in separate files near
viewcontents.html instead of writing them inline.
Core: disable sidebar by default.
Core: enable SB2 by default.
LHTR: <Tab> to indent paragraphs.
LHTR: removed some debugging output.
LHTR: support wrapping in a link arbitrary content.
Core: moved Sidebar to defunct plugins.
AN: hopefully fixed alert() behavior on X11.
Merge branch 'master' of github.com:0xd34df00d/leechcraft
Azoth: fixed activation sequence.