lexer: improved OF hack
ast: Node::expandSlice
closes #96; implemented unary spread
fixed `f! in o`
0.6.4
optimized `x of o[p, q]`
made unaries spread recursively
made `case a[b, c]` work as expected
fixed a bug where for-to/til messes following in/of
made `instanceof` complain on bad operands
0.6.5
closes #97; implemented unary assign
fixed `do [f, g]`
ast: Unary/Binary <- Op
coffee#1703: fixed `- --@a`
fixed `!+=@n` etc.
optmized binary `!?`
`a? <<< b` is now short for `a !? a <<< b`
ast: optimized compileMinMax
fixed `unless +=x`