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.
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.
Merge pull request #2595 from kiith-sa/patch-2

(trivial) (ddoc) more descriptive std.concurrency doc.
Merge pull request #2596 from MartinNowak/metastrings

readd std.metastrings as deprecated module
Merge pull request #2572 from MartinNowak/asmAttributes

attributes for inline asm
Make std.file.readLink safe
Mark a unittest for std.file.thisExePath as safe
Make std.file.DirEntry._ensureStatDone safe
Merge pull request #2600 from tom-tan/safe-unittest-file-thisExePath

Mark a unittest for std.file.thisExePath as safe
Merge pull request #1453 from quickfur/chunkBy

Implement groupBy.