Add Moving 10 lines functions and Use Meta key to split screens

Add key bindings for M-n, M-p
- M-n Cursor Move Down 10 Lines
- M-p Cursor Move Up 10 Lines

Delete Key Bindings for C-x 1, 2, 3, 0, 0
- Change it to M-1, 2, 3, 0
- Add C-M-o to switch beween windows

Change the line highlight color to grey.

-- Edited by Jerry Shan