Rename and move some specs
Improve spec coverage for handler functions

The specs now check all possible handler functions.
Spies are used to simplify the assertions.
Support long and shorthand callback handlers

Before, only "onstate" and "onevent" were supported. Now "onenterstate"
and "onafterevent" can be used, too. They take precedence over the
shorthand versions if both are present.
Merge pull request #4 from theGoodEvil/support_all_handlers

Support onenterstate and onafterevent handlers