Better directive handling

[za-creature]

Closes #540

Changes:

1. Changes the semantics of coffeelint-enable:

   From: enables all rules that were previously disabled by a coffeelint-disable directive
   To: resets the ruleset to whatever was originally specified in coffeelint.json

   This is because the current implementation is buggy and mixes immutable with mutable structures. While there are ways around this, it makes the code needlessly complex and not that much useful.

   Example of existing bug

   # coffeelint: enable=no_implicit_parens
   # coffeelint: disable=no_implicit_parens
   # coffeelint: enable
   foo "bar"  # error

   # coffeelint: disable=no_implicit_parens
   # coffeelint: enable=no_implicit_parens
   # coffeelint: disable=no_implicit_parens
   # coffeelint: enable
   foo "bar"  # no error

2. Adds the following directives that work like their parents but only for the current line

   • coffeelint-disable-line=foo,bar,baz
   • coffeelint-enable-line=foo,bar,baz

3. Overloads coffeelint-disable to disable all registered rules. Primary use case:

   # coffeelint: disable
   do bad shit here
   # coffeelint: enable

   This contrasts with the primary use case for the parametric version which is:

   # coffeelint: disable=foo
   do shit "foo" would complain about
   # coffeelint: enable=foo

4. Adds support for directive shortcuts. Also defines the first shortcut # noqa that expands into coffeelint: disable-line

[AsaAyers]

Thanks for adding this.