Merge branch 'develop'

* develop:
  remove flag and pem params
  make handlerManager invisible
add Namer and Leveler interface; Open register and unregister interface
split interface
split interface
Merge branch 'master' of https://github.com/Xuyuanp/glogger

Conflicts:
	glogger.go
edit readme
change filter interface
make Handler as a Namer and a Leveler
add ConfigLoader
add register for each component
formatter load config
add register and getter for all components
suport python style json format config
edit readme
Update README.md
SmtpHandler support loading config
rename loggerMapper to loggerManager
add friendly error message
reformat code
add comment