add definition for glob

[dongzhuoer]

maybe the order can be adjusted as

// Obtain an R environment
Environment stats("package:stats");
Environment env( 2 ); // by position
Environment glob = Environment::global_env();

// Special environments
Environment::Rcpp_namespace();
Environment::base_env();
Environment::base_namespace();
Environment::empty_env();

[eddelbuettel]

Please STOP submitting PRs now and read this document about process first

One small one I let slip, two I am not pleased with. Three is clearly out of bounds.

All these are in the same effing document. Please pool resources and discuss first as the Contributing.md document you are being shown on each PR you make asks for.

[dongzhuoer]

I'm so sorry.

[dongzhuoer]

Moved to #933

[dongzhuoer]

implemented in 6100a55