New opAssign unittests in std.array.array
Simplify T* emplace(T)(T* chunk)
tweak trustedMemcpy in emplace
Change messages in emplace to use format
makes to! string to string safe
ctfe unittest for to!string,string
Fix Issue 11108 - `hasElaborateAssign` should check whether the type is assignable

Issue URL: http://d.puremagic.com/issues/show_bug.cgi?id=11108
enforce thisTid was called before calling receive

- Simply calling receive in main as stated by the comment
  makes no sense, as nobody could send a message.
fix Issue 10357 - std.typecons.Nullable!(SysTime).Nullable.__ctor!() error instantiating

Add a workaround until qualified postblit is properly implemented.
Use documented unittests for `std.traits.isAssignable`.
[Refactor] Remove redundant parantheses in `std.traits.isAssignable` unittest.
Support degenerate bitfields with fields of length 32 and 64 to match documented constraints.
Add unittests for bugs which seem to have been fixed over time.
Properly scoped and selected the import of std.traits in std.ascii, so that it is only imported for the 2 functions that use it, toLower and toUpper.

There are also a couple of style changes, namely the ordering of values in an anonymous enum, and the use of only 1 indent level within an array declaration. The final change is to mark toLower and toUpper explicitly as @safe pure nothrow, as these are checked in unittests, but a unittest wouldn't tell you what was causing one of the attributes to not be valid for them.
Merge pull request #1556 from dawgfoto/fixMessageBoxInit

enforce thisTid was called before calling receive
Merge pull request #1609 from Orvid/master

Scoped the imports in std.ascii
the enum caused it to allocate needlessly. static immutable avoids that.
Merge pull request #1615 from adamdruppe/md_allocation

the enum caused it to allocate needlessly. static immutable avoids that.
Merge pull request #1613 from Safety0ff/master

Support degenerate bitfields with fields of length 32 and 64
std.process: Fix spawnProcess in Windows GUI programs (issue #11180)