add a simple introduction
Merge pull request #3 from shanzi/master

完善 osx demo，添加音量和duration 控制，兼容 iOS ，添加iOS Demo
Merge pull request #4 from shanzi/master

create delegate for bellplayer
Merge branch 'master' of https://github.com/xiuxiude/bell

Conflicts:
	README.md
Use NSNotification for player
fixed OS X version

drop iOS < 7.0 support
Merge pull request #5 from AnakinMac/master

Use NSNotificaion and some other improvements
iOS demo and retab
Add License
add bell.podspec
Merge branch 'master' of github.com:shanzi/bell