slightly changed dependent product syntax
added convenience constructor for variable-lifetime map
predicate for 'no mutable loans' on a bank. renamed borrow to make-loan.
shortened 'Context' to 'Cxt'. ty-bound-by-lifetime predicate
removed the * constructor for Routes (b/c addresses don't include pointer dereferences)
Path eval now derefs pointers to support removal of * from Route. Added predicates for freezability, uniqueness, and validity of paths.
Void layouts are a datatype rather than a function now.
Moved layout-shape relationship to Shape. Judgments for borrowing a path. Judgments for checking reads and writes based on loans.
Added & expression with typing and eval.
Merged push and region (push increments both var count and lifetime val count). Added lifetime map for checking.
Merged pop and end traces (to go with merge of push and region). Added lifetime map.
Added lifetime map to Configs. Added fn-ok proofs to Config checking.