Saturday morning coding time....

This adds a gamma Node in Math>Vector, for those who want to quickly adjust the gamma of a texture (or something else)
nodewise without fiddling with lightwave function node.

nothing big, I know, but I wish I had this long before and know to use it.

for lw 11-2015 and 2018 and above

as said quickly slapped together, should work as expected, but this hasn't gone through extensive testing