Gamma Correction and SVN

Hello,

I do like to get the latest jme3, and I saw it supported Gamma correction, but is it possible to svn checkout that version? Because I cant find it anywhere, and I need to modify some files of the Engine for my game.
If the gamma correction is implemented in the shaders, thats cool.

Sorry for my bad English, I really dont know how to ask this question in English…
I mean something like: how to get the source of the latest Engine version?