修复了一个潜在的bug

第一次进入应用后，默认会载入一条微博，但是这样就会导致footer-view被删除，无法刷新，so，取消之前的做法
添加了一个日期处理类，线程安全的
使用新的datetime日期处理类去处理日期的解析
add git attr file

keep the same line-sepatate across platfrom and differenet git client settings.
bug fix.

微博时间线列表每个条目均可点击了，并且每个条目里每个可点击的都有自己的监听事件。
refactors.
fix the actionbar menuitem' s selector issue.

see my post answer on stackoverflow for detail:
http://stackoverflow.com/questions/13652368/using-a-selector-for-a-menuitem-in-the-actionbar/21911466#21911466

also, refactor the selector' s name:-)
make the drawer' s latest tweet clickable!

also, a little refactors for var defined.
add google analytics support.

should make it a preference for those who won' t be tracked.
add google analytics preference.
preference refactors.

move the pref keys to R.string.xxx
update README