add matrix:export
add api document (unfinished)
Added method to close window by pressing 'q'
minor edit for also considering 'Q'
Now can gracefully close a window
oops forgot break in switch.
forgot break in switch again...
Merge pull request #33 from yzhwang/master

Fixed the X11 exiting error.
Merge pull request #4 from cloudwu/master

合并