**BUG**
Concise problem statement:
Cursor gets stuck in right-click-and-hold dragging the canvas.
See also:
>https://easyeda.com/forum/topic/Right_mouse_inconsistant_sometimes_sticks-dNHZSasKE
Steps to reproduce the bug:
1. Right-click-and-hold to drag the canvas;
2. Move the cursor outside the canvas;
3. Let go of the right click;
4. Move the cursor back inside the canvas;
Results:
When you move the cursor back into the canvas area, it will continue to drag the canvas.
To escape from this, you have to do another right click.
Expected results:
The cursor should not drag the canvas.
Browser:
Chrome & Firefox on Win7 and Linuxmint KDE 17.2 (Ubuntu 14.04 LTS)
