Make std.file.mkdir safe
Use std.windows.syserror.wenforce instead of cenforce on Windows
Fix the documentation for mkdir
attributes for inline asm
std.mmfile: Improve error handling

Use wenforce instead of (inappropriately) errno.
Switch from if blocks to scope blocks.
std.mmfile: Fix Windows anonymous mapping creation to conform to MSDN
Add setProxyAuthentication() in std.net.curl
Implement chunkBy.
Implement binary predicate for chunkBy.
Move std.range.chunkBy to std.algorithm.groupBy.
Refactor to eliminate redundant call to r.empty.

.savePrev and .prev should be private.
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
Merge pull request #2592 from IgorStepanov/datetime-test-fix

[trivial] fix datetime test
Make std.file.symlink safe
(trivial) (ddoc) more descriptive std.concurrency doc.

`ownerTid`/`childTid` are more descriptive/obvious when reading than just `tid` here.
Merge pull request #2594 from tom-tan/safe-file-symlink

Make std.file.symlink safe
readd std.metastrings as empty and deprecated module

- Removing the deprecated module silently broke
  and code that still imported the module without
  using any of it's functions.