res:dock:: fix app status problem.

app gets wrong status when opened.

reason:
the status is not changed after opening animation.
Merge remote-tracking branch 'origin/master' into develop
res:dock:: fix tooltip problem.

closing preview will lead to tha fact that tooltip shows failed.

reason:
setting the dock state to non-hover on Preview_close_now.

solution:
add a global variable $tooltip to hold tooltip.
Merge branch 'develop'