Fix nil bug in templates cache module.

1. fix nil bug of tplcache.
2. make InitLogger() function available for public.
Enable multiple directories in one tplcache.
Change password base64 table characters.

1. change '+', '/' to '-' and '_' for adapting to use in url.
Use init function to instantiate essential things.
Reorder initialization steps.

1. only init logger system before call start server method.
2. init configs, default templates cache and session manager after call
start server method.
Merge pull request #11 from ggicci/dev

Dev