add support for previous unsupported special forms

[fasfsfgs]

Some special forms were left out of #15 because they didn't follow a common pattern as others special forms.
Those are: '.', 'new', 'fn', 'set!'

I added their signature support manually because of one of the reasons below:

• Their doc-strings were lacking correct info to build a proper signature helper (I based signatures on the online documentation of special forms and java interop);
• The logic necessary to extract their signature support based on their non-standard doc-strings would be too great for just a couple of cases.

closes #16

[avli]

Hi @fasfsfgs,

Great job as usual. Glad to see you again ;)

[fasfsfgs]

@avli Thanks =D
I wish I had more time to work with this but other stuff comes in the way.
I'll keep helping here as often as I can. =)