Small Feature Request: Please let me reorganize the tabs for open trees

[FrostBear]

A very simple request here.

Currently, when opening up multiple files, SpeedTree does not allow for the reorganizing the order of tabs on the top of the screen. While not a major issue, it can become needlessly chaotic when many files are open at the same time as I can't control the order of the tabs without closing all the files and opening them up again in the order that I want.