Also fixed Clang-tidy modernize-redundant-void-arg, readability-container-size-empty, and some readability-simplify-boolean-expr warnings.
Alphabetical order of STL headers.
Fix some misspellings.
Big search and replace to change name of internal namepace so it's mangled with the Boost version number - the aim is to reduce the chances of mixing different header and library versions.
