Wait for multiple vars

[jamesplease]

Promises have a method that allows you to wait for N promises to resolve:

Promise.all( p1, p2, ... );

Should this library implement similar behavior? Possible syntax:

futureVars.promised( 'var1', 'var2', 'var3' );

futureVars.promised( ['var1', 'var2', 'var3'] );