Support for attributes without parenthesis

[maddes]

I haven't looked the code yet, but will ASAP.

In the meanwhile, I let here my idea.
The parenthesis could be replaced by a simple comma, for example, this:

a(href: '/login', title: 'View login page') Login

Could be written like this:

a, href: '/login', title: 'View login page' Login

The rationale is simple: is there a comma? then an attribute is comming

[kylekatarnls]

But it's not Jade syntax. jade.php must match with the JS engine.
However, with the JS one, we can write it with no comma:

a(href="/login" title="View...") Login

I implemented it in my fork.