OSL statistics output includes version and major options.

This is so that when viewing a log containing OSL ShadingSystem
statistics, we can be sure which version of the library it was, and how
the most important options were set.

Example output looks like this:

    OSL ShadingSystem statistics (0x7ff65c005a00) ver 1.5.7dev
      Options:  optimize=2 llvm_optimize=0 debug=1 llvm_debug=0 lazylayers
                lockgeom_default range_checking
      Shaders:
        Requested: 1
    ...