dropping parentheses on template instantiation

[Yigal Chripun]

if "!" is removed from template instantiation than perhaps it could be
used as part of identifiers in the future?

Ruby uses the following convention which I like:

sort(array) // *new* sorted array is returned

Vs.

sort!(array) // sort array in place

Ruby also uses ? for boolean functions, so

isValid(something)

will be in Ruby

valid?(something)

the ? can't work right now in D due to ?: ambiguity, i think.