ANN: LazyContext

I’ve released LazyContext 0.1.0. It brings accessible environments, and lazy evaluation within environments, to Julia. This means that functionality in R that relies on this, like formulas, dplyr-like querying, etc. finally becomes available to Julia users. There is a performance cost, though I’ve included a workaround (evaluate instead of @evaluate). @davidanthoff, I have some specific ideas about how this can be harnessed for an alternate interface to query.