* removed statement sequencing in favor of PLT Redex lists in blocks
* blocks are now their own nonterminal in Patina
extend gitignore with .swp files
Type contexts now use PLT Redex sequences instead of linked list.
Type contexts are now a language extension.
Replaced Γ-extend with equivalent Racket code.
Renamed Γ-extend-many to Γ-extend.
removed spurious TODO
formatting
Rewrite Γ-extend to use racket instead of recursive calls.
A couple property tests.
Evaluation and some other stuff.