Fixes #3117.

 - The Iterator type is trivial; passing it by const&.
 - The std::string root is invoked only on const& strings, so
moving it does not save anything in this context.

Mostly in the file headers.

find *Lib -type f | xargs sed -i 'N;s%^\s\+\*\n\(\s\+\*/\)%\1%'

Fixes multiple copyright messages in the doxygen docu.

ag '\\file' -L --ignore=ThirdParty *Lib |xargs  sed -i 's/\(.*\)\\copyright/\1\\file\n\1\\copyright/'

Most of the current .clang-tidy contained checks:
google-explicit-constructor
google-readability-braces-around-statements
modernize-loop-convert
modernize-use-default-member-init
modernize-use-emplace
modernize-use-using
readability-braces-around-statements
readability-else-after-return
readability-named-parameter
*readability-namespace-comments
*readability-inconsistent-*
readability-redundant-member-init
readability-simplify-boolean-expr
readability-string-compare
*explicit-conversions*

clang-tidy modernize-use-transparent-functors check.

[[noreturn]] attribute is supported by now.

Update documentation mismatches in other getConfigAttribute*().

Clang format run on near-the-header lines.

Happy New Year

Unfortunately the Visual Studio 2015 does not support
the platform independent style for the function attributes.
Although it is a c++11 standard.

This potentially saves a second copy compared to using const
reference. See Effective Modern C++, Item 41.