Refiled "Rename UFCS to accurately reflect its functionality"

[Centril]

Refiling rust-lang/rfcs#1140

UFCS ("Unified Function Call Syntax" #132) ended up being merely an "unified syntax", but not specific to functions and less so to calls.

It also doesn't allow calling free functions like methods, like D's UFCS does.

To avoid turning our feature into another RAII-AA ("Acronym Accident"), I propose renaming it to AILS ("Associated Item Lookup Syntax").

[Havvy]

This was already done. See https://doc.rust-lang.org/nightly/reference/expressions/call-expr.html#disambiguating-function-calls

[Centril]

Cool; Closing then.

[eddyb]

FWIW I am lately partial to "type-qualified" (<T>::) and "trait-qualified" (<T as Trait>::) without using "fully-qualified" at all. cc @nikomatsakis