load stdlib relative to pixie-vm location
add -l, --load-path option
add IEmpty protocol for collections
add tests for first
return nil when nth is out of range on arrays

this also fixes `first` on arrays, which is especially useful when
destructuring arguments in a function.
expose an internal version of -defprotocol

it's internal because we probably want to enable multi-arity protocol
methods and implement a `defprotocol` macro like clojure has.
bug fix
reorder rules to look nicer
Merge pull request #60 from heyLu/load-paths

Fix load path issues
Merge pull request #63 from andrewchambers/read-eval

Reader and eval work.
support running only a subset of the tests
Update binary name
Merge pull request #65 from heyLu/collection-bits

Collection bits and running tests selectively
Merge pull request #66 from jgdavey/patch-1

Update binary name
Make PersistenHashMap conjable
Merge pull request #69 from thomasmulvaney/master

Make PersistenHashMap conjable