only put test/clj on :test-path in project.clj. fix busted type

inference test. comment out repl test - spews errors.

CLJS-752: implement specify!

redefine specify in terms of specify! which directly modifies instances.

wicked fast

add ICloneable protocol, implement for persistent collection types, add

clone function

fix disj 2 arity bug for case where coll is nil

CLJS-724: Range -first bug

Don't return start if Range is empty

add some basic inference tests

decomplect type hints & fns

stop using :tag, fns now are always tagged 'function, and the type-hint
is instead attach to :ret-tag. Add type inference case for :throw, just
'ignore. We now have warnings if you try to add numbers and functions.

don't put the entire methods AST into namespaces for supporting

inference, just :max-fixed-arity, :variadic and the :tag

infer more cases, we need to deal with forward declare issues explicitly