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
add docs to install target
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.
std.process: Fix spawnProcess in Windows GUI programs (issue #11180)
Merge pull request #1491 from monarchdodra/toSafe

makes to! string to string `@safe`, `pure` and `CTFE`-able
Merge pull request #1528 from monarchdodra/arrayEmplaceFixup

Fixup unittest following emplace fix
Merge pull request #1552 from monarchdodra/emplaceFixup

Emplace fixup
Fix Issue 11196 - `std.range.zip` fails to compile if range elements aren't default contructable

Issue URL: http://d.puremagic.com/issues/show_bug.cgi?id=11196
Merge pull request #1619 from denis-sh/fix-Issue-11196

Fix Issue 11196 - `std.range.zip` fails to compile if range elements aren't default contructable
Clarify `isAssignable` documentation. Add private `isRvalueAssignable` and `isLvalueAssignable`.

Previously `isAssignable` worked like `isLvalueAssignable`.

Also add some unittests.
Merge pull request #1597 from denis-sh/fix-`std.traits.isAssignable`

Fix `std.traits.isAssignable`
Merge pull request #1618 from CyberShadow/std-process-gui-spawnprocess

std.process: Fix spawnProcess in Windows GUI programs (issue #11180)