more flexible signing

if you want to build samples with custom signing keys, add a samples/gradle.properties like this:

storeFile=/path/to/keystore/file
storePassword=xxx
keyAlias=yyy
keyPassword=zzz

if you don't want to build samples with signing keys, simply remove samples/gradle.properties.
delete junk
Merge branch 'dev'
Invoke onScrollOverThreshold when STATE_DRAGGING only
Signed-off-by: Issac <issac@imid.me>
修正4.3上滑动闪屏的问题

Signed-off-by: Issac <issac@imid.me>
Merge pull request #2 from huahang/master

merge mor flexible signing
新增OverrideExitAnimation方法
使退出动画与滑动返回相同。

Signed-off-by: Issac <issac@imid.me>
修正Activity没有正确Finish的情况

Signed-off-by: Issac <issac@imid.me>
修正Layer的问题
添加SwipeBackPreferenceActivity
重构，通过SwipeBackActivityHelper可以支持更多 Activity
add demo for using Actionbar sherlock
sherlock samples
Translucent
fix PreferenceActivity null pointer exception
使SwipeBackLayout的属性可在 xml 中配置
Merge branch 'dev'
using defstyle
hacky fix: 与photoview的缩放手势冲突
修正滑动判断不精确的问题