Typecheck == and !=
Typecheck array accesses and make sure the typer descends into everything
Check that the left-hand side of an assignment is a lvalue
Typecheck method calls
Get rid of an isInstanceOf check
Inline a method call
Simplify a Boolean expression
Return type of left hand side as type of assignment operator
Lvalue -> LValue
Merge pull request #109 from jspam/039-even-moar-typer

Finish the typer (almost, haven't checked against the spec yet)