std.file: Make rename clobber on Windows, adjust docs (Issue 5032)
std.file: Document and test that copy clobbers
Enable test lines that had been blocked by issue 2486
Merge two opEquals into one

This did not work by compiler bug, but does now.
Improve test cases for qualified objects

By fixing issue 8669, they are now working properly.
Enable test line that had been blocked by issue 7641
fix Issue 8655 - bitfields and Typedef don't mix

Support built-in properties
Use unary std.traits.isAssignable
fix Issue 8613 - std.typecons.Proxy cannot work with operator 'in'
Merge pull request #1198 from CyberShadow/fix5032

std.file: Fix/document/test clobber behavior for copy and rename (Issue 5032)
Merge pull request #1200 from 9rnsr/improve_Proxy

Improves for std.typecons.Proxy