Mochi

* Change the trailing closure syntax so that a trailing closure expression is passed to a function as the function’s first argument
* func() (args) -> closure_body
* Introduce the trailing closure syntax so that a trailing closure expression is passed to a function as the function’s final argument
* func() : (args) -> closure_body

* Modify the record statement to be able to specify a non-record class as a parent
* Replace '-' in name of the builtin functions with '_'
* Fix some bugs

* Support the trailing closure syntax
* Support the slicing and indexing syntax
* Implement short form for keyword arguments and dict keys

* Implement raw strings. Fix a bug in strings
* Add support for multiple imports from single source
* Change the dot_expr to be able to specify a reserved word as a attribute name
* Modify REPL to be able to exit with CTRL-D

* Modify the type of the take function to pvector from tuple
* Modify the eval function
* Change the display contents of an exception information

* Add the !> operator, the !&> operator and the distinct function