Fix a typo

Stab ->
Stub
  ^
Merge pull request #406 from kou/fix-a-typo

Fix a typo
update dependency
use File.exist? instead of File.exists?
fixed warnings: shadowing outer variables.
update dependency
remove unused variables
add theme_online plugin #291

* add misc/plugin/theme_online.rb
* change theme name style from "name" to "location/name"
* add new methods named as "theme_list_*" and "theme_url_*"
* bring javascript code in 00default.rb to 01conf.js
Merge pull request #408 from tdiary/291_theme_online_plugin

add theme_online plugin #291