[osg-submissions] propose split out GL2Extensions.cpp?

[Mike Weiblen]

Hi Robert,

I'd like to propose splitting Program.cpp, creating a GL2Extensions.cpp;
there is already a GL2Extensions.h.
Program.cpp is just too unwieldy, and it would better mirror the
structure of the existing GLExtensions.cpp.

I can send a submission if you agree.

-- mew