refresh index content & add more info to network and android-jotting
Merge branch 'master' of github.com:DanielDong/DanielDong.github.io

Conflicts:
	index.md
add more info to recommend-system
Merge branch 'master' of github.com:DanielDong/DanielDong.github.io

Conflicts:
	_posts/2014-07-23-recommend-system.md
add more info to android-listview & command-line & recommend-system