Merge branch 'julia0.6'

diff --combined README.md
index fbb2603,6f30a15..a6e0645
--- 1/README.md
--- 2/README.md
+++ b/README.md
@@@ -6,7 -6,7 +6,7 @@@ that which it has already fulfilled: fo
  how forth works. 
  
  This package owes a massive debt to the existence of the literate programming
 -project [JonesForth] (https://rwmj.wordpress.com/2010/08/07/jonesforth-git-repository/),
 +project [JonesForth](https://rwmj.wordpress.com/2010/08/07/jonesforth-git-repository/),
  which was an amazing read. To a large degree my package is simply a port of
  that project from x86 assembly + forth to julia + forth, although the mapping
  is in a few places non-trivial due to the fact that julia is a high level
@@@ -26,8 -26,8 +26,8 @@@ install it, you will therefore need to 
  
      julia> Pkg.clone("https://github.com/tgvaughan/forth.jl")
  
- Currently, forth.jl **requires** Julia 0.5. (Incompatabilities between 0.4 and 0.5
- mean that I cannot support both versions.)
+ Currently, forth.jl **requires** Julia 0.6. (Incompatabilities exist between
+ 0.6 and previous versions of julia, particularly the handling of [world age](https://github.com/JuliaLang/julia/pull/17057).)
  
  ## Usage