Make std.file.mkdir safe
Use std.windows.syserror.wenforce instead of cenforce on Windows
Fix the documentation for mkdir
Fix the arguments for std.windows.syserror.wenforce
Fix 9906: unaryFun and binaryFun should recognize static opCall

Structs or classes with static `opCall` should be recognized as valid
function objects.
Update ddocs.
Revert AA/array extension to unaryFun.

Per PR discussion.
Parameterize a string type for error message
Add missing std.traits.isSomeString
Fix broken case of function object with non-static opCall.
fix doc
Move prefix member function attributes to postfix
Merge pull request #2556 from quickfur/issue9906

Fix 9906: extend unaryFun and binaryFun to recognize function objects
Merge pull request #2585 from 9rnsr/fix12931

Move prefix member function attributes to postfix
Merge pull request #2583 from MartinNowak/doc

fix doc
Merge pull request #2570 from tom-tan/fix-windows-syserror-wenforce

Fix the arguments for std.windows.syserror.wenforce
use sum instead of reduce in example code
Merge pull request #2590 from MartinNowak/docs

use sum instead of reduce in example code
Merge pull request #2560 from tom-tan/safe-file-mkdir

Make std.file.mkdir safe
fix datetime test