Add alignment_of implementations
Refactor details of alignment_of
Add note to alignment_of documentation
Add more tests.
Add back function pointer test.
Correct namespace of alignment_of, and test usage
Merge pull request #1 from boostorg/pull-request/more-alignment_of-tests

Add more tests
Update alignment_of implementation and test
Minor documentation improvements
Eliminate clang warnings in test code
Workaround alignment_of for all versions of VC
Further VC alignment_of support
Minor formatting issues
Simplify MSVC alignment_of implementations