Coding style fixup for PR 2500.

As requested by Andrei.
Wholesale coding style fix for std.numeric.
Merge pull request #2552 from quickfur/sumOfLogs_fixup

Coding style fixup for PR 2500.
Fix 9906: unaryFun and binaryFun should recognize static opCall

Structs or classes with static `opCall` should be recognized as valid
function objects.
Implement unaryFun!AA as function mapping keys to values.
Implement unaryFun!array as function mapping size_t to elements
Update ddocs.