Fix drag in range of text in the lyric editor might have performance issue.

[andy840119]

Root cause might be onHover() in the EditorableLyric? Should ignore the hover event if the lyric is not drag in the current lyric?

用中文來說 可能的原因是，假設在 lyric 1 正在 dragging 去選取文字範圍 ，但是滑鼠移動到 lyric 2:

• lyric 1 會收到 dragging event
• lyric 2 會收到 hover event

或許最根本的原因可能是，dragging 的時候不應該觸發其他 drawable 的 hover event?

[andy840119]

Maybe should check the mouse state in the hover event?

[andy840119]

順便需要調整那些 method 的順序 之前寫得有點亂

[andy840119]

Fixed.