Apply Clang tidy modernize & performance

[ricrogz]

Just what the title says. I did (each in one commit):

• clang-tidy -fix -checks='modernize*,-modernize-use-trailing-return-type' *pp -- -std=c++11 (no manual editing).
• The previous command pointed out that deleted constructors and assignments should be public, so I manually moved them into public: blocks.
• clang-tidy -fix -checks='performance*,-modernize-use-trailing-return-type' *pp -- -std=c++11 (no manual editing).

clang-tidy was used from LLVM version 9.0.1. I disabled the "modernize-use-trailing-return-type" because it is annoying (changes function declarations to something like auto whatever() -> return type. I also find it slightly annoying that clang-tidy insists on adding #include <utility> to the headers, but decided not to remove it.

Checks passed on all three platforms (after bumping MacOS version): https://dev.azure.com/ricrogz/mymaeparser/_build/results?buildId=471

[ricrogz]

Updated. I reran clang-tidy, and it seems stable.

Also, I noticed the build failure in appveyor -- it looks like we use VS 12, and it doesn't understand noexcept. Do you think we should bump the VS version, @d-b-w ?

[ricrogz]

Also, Travis is not running anymore ?

[d-b-w]

Thanks, Ricardo!