Syntax: Function arguments

[eduardo-imadeira]

closes #43

• Change the parser to accept multiple sets or arguments in parenthesis (trivial)
• Automatically translate (x:Int | p) : Int to (x:{x:Int | p }) -> Int = \x ->
• Change the type grammar rule to accept (x:Int | p) instead of {x : Int | p}
• Add support to also accept (x:Int) instead of {x : Int | p}

about the last 2 checkboxes, I didnt remove the support to the old syntax, now supports both syntaxes, as we can see in the file 'aeon/examples/sugar/function_main.ae':

def fff : (z:Int) -> (f: (a:{k:Int | 1 <= k && k <= 10000}) ->( b:{m:Int | 0 <=m} ) -> Int ) -> Int = \b-> \a-> b+ a(2)(3);
def fff : (z:Int) -> (f: (a:Int | 1 <= a && a <= 10000) -> ( b:Int | 0 <=b) -> Int ) -> Int = \b-> \a-> b+ a(2)(3);