VS 2017 has an annoying bug, where the result of `__FILE__`
substitution is always lower-cased. This breaks approval tests
and I am not quite convinced that we should fully normalized paths
to accomodate this bug.
We need to remember to undo this in the future though.
Also had to add new project to redirect CTest output, add
separate batch scripts for AppVeyor because it doesn't handle
multi-line batch scripts in yaml properly, and other helper
scripts.
- Added new compilers and OS X images
- Option to run SelfTest under Valgrind
- Merge "Debug" and "Release" configurations into one run
-- This saves apt setup and cmake download step per compiler, 60-90s
- Fix C++14 compilation under Clang 3.8 and up
