delete readme in develop branch.
add a new readme file in develop branch.
Fix the bug that the program could not recover after the user press the left up close button.
Merge pull request #16 from whmsysu/master

Fix the bug of recovering window
fix the misplaced view warnings.
Merge branch 'develop'

Conflicts:

ShooterSubX.xcodeproj/project.xcworkspace/xcshareddata/ShooterSubX.xcche
ckout

ShooterSubX.xcodeproj/project.xcworkspace/xcuserdata/song.xcuserdatad/Us
erInterfaceState.xcuserstate