Request: Add Support for multiline values

[MattDiMu]

Autocompletion for multiline values doesn't work as expected. This concerns mainly sass-maps, which are usually not written in one line due to readability reasons. e.g.

$map: (
  value: 123,
  color: #FAF
);

is shown as

$map: (

It would be great, if the line breaks and unnecessary spaces would be removed in the preview:

$map: (value: 123, color: #FAF)

Btw, this also affects the incoming pull request #5. When used on a mixin like

@mixin someMixin(
  $required-param,
  $optional-param-1: 1,
  $optional-param-2: 2,
  $optional-param-3: 3,
)

the preview AND the inserted text are wrong:

@include someMixin(

better:

@include someMixin($requiredParam, $optional-param-1: 1, $optional-param-2: 2, $optional-param-3: 3);

or (inserting only required params):

@include someMixin($requiredParam);