v2.0.0

Breaking changes:

• stampit() now receives options object ({methods,refs,init,props, static}) instead of multiple arguments.
• All chaining methods return new stamps instead of self-mutating this stamp.
• state() always shallow merge properties. It was not doing so in a single rare case.
• Instead of factory arguments the enclose() functions now receive the following object { instance, stamp, args }.

New features:

• stampit() now receives options object ({methods,refs,init,props,static}) instead of multiple arguments.
• Instead of factory arguments the enclose() functions now receive the following object { instance, stamp, args }.
• New stamp.props() method for deeply merged state.
• New stamp.static() method which add properties to stamp, not an object.
• state deprecated. refs must be used instead.
• enclose deprecated. init must be used instead.
• All API functions have shortcuts now. I.e. you can write stampit.init() instead of stampit().init(). Same for methods, refs, props, static.
• All unit tests are now on tape instead of mocha+should.