Specify blocks as taking no parameters, not unspecified parameters

[jmah]

A block or function with parameters () means "unspecified parameters", so the following code compiles and runs without complaint:

void (^clearToken)() = ^{ ... };
clearToken(@"hi", 13, NO);

Change to (void) meaning "no parameters". Also standardize on ^{ to open a block with no parameters (from a mix of ^{ and ^() {).

[chrisp-fb]

hey jmah@ - thanks, we accepted this and pushed it in the release today but forgot to accept the actual pull request on the dev branch.