Code optimization,  add settings to config, fix typo

init: added check cache, rewrited markdown autoloader:
replaced class with static method to closure.

Userguide: optimized the methods: _modules(), action_*,
add method config() for easy access to config 'userguide',
moved styles & scripts in config,
added Google translate, updated Disqus.

Views: fix typos, optimized code.