add ExpandableTextView（可展开和收缩内容的TextView）

可已展开收缩内容的TextView。  
项目地址：https://github.com/Manabu-GT/ExpandableTextView
Merge pull request #84 from zhengxiaopeng/master

Add ExpandableTextView
add TextDrawable
Added Gitter badge
Merge pull request #85 from QichaoChen/master

add TextDrawable
Merge pull request #86 from gitter-badger/gitter-badge

Add a Gitter chat badge to README.md
Code format
Modify QQ
add SAF
Update README.md
Merge pull request #87 from fengzhizi715/master

add SAF
Merge pull request #88 from pungrue26/patch-1

Add SelectableRoundedImageView
Merge pull request #2 from Trinea/master

同步代码