Fix issue 10165 (rework of PR #1302)

http://issues.dlang.org/show_bug.cgi?id=10165
Issue 10165: No syntax to create thread-local shared variables

Adds `UnqualRef` templated alias/struct that is similar to Rebindable but
strips away all qualifiers completely (including shared)
Fix issue #13354 - Use a generic Variant for passing opIndex/opIndexAssign arguments.

Also improves the error message when an incompatible index or value type is used by printing the actual type ID instead of "void[]" in the thrown exception.
Add @nogc to RebindableCommon methods
Reverse static condition in Rebindable/RefUnqual
Make std.file.timeLastModified with two arguments safe
Merge pull request #2474 from tom-tan/safe-file-timeLastModified-2

Make std.file.timeLastModified with two arguments safe
Use reinterpret cast is [does|may]PointTo

Instead of a straight up cast. Avoids problems related to opCast
or alias this, such as those in:
http://forum.dlang.org/thread/vldwvnuivsfwjozqiuup@forum.dlang.org
Eliminate C-style array declarations.
Use auto instead of explicit array type.
Merge pull request #2475 from quickfur/issue13402

Eliminate C-style array declarations.
Fix Issue 13391 - Allow division of BigInt by long/ulong
Fix some property enforcements.
Merge pull request #2479 from denis-sh/fix-some-property-enforcements

Fix some property enforcements.
Change unittest from writing output to concatening to an array and checking the content
Merge pull request #2480 from MetaLang/tee-unittest-fix

Change unittest from writing output to concatening to an array and checking content
Add empty check for haystack range r in skipOver()

Remove space
Merge pull request #2481 from nordlow/empty-skipOver

Add empty check for haystack range r in skipOver()
Add @nogc to bitfields accessors
Remove pure nothrow @nogc from input range version of byXchar

The functions are templated and get their attributes deduced.
Merge pull request #2484 from sinkuu/nogc_bitfields

Add @nogc to std.bitmanip.bitfields accessors