Added -t option to parser.coffee

This option prints the result of tokenizing the expression rather than parsing it.
Removed the `dot` type and added the `symbol` type

Symbol literals consist of a FULL STOP followed by any valid identifier, e.g.:

.a

[.a, .b, .c]

foo = {
    .bar: 1
}
foo.baz = 3
foo.bar # => 2
foo.baz # => 3