* Make `enforce-clang-format.cmd` also run `git diff`. This will produce more informative output for clang-format failures.
* Also add timeouts to every task in `run_build.yml`.
* Also remove default `targetPlatform` from `run_build.yml`. This is provided by `azure-pipelines.yml`.
Add jobify.exe and parallelize.exe
Add a "tools" directory for test/build support tools.
Add jobify.exe from the msvc repo.
Extract parts of jobify into stljobs.h, and author wrappers for other test support.
Add parallelize.exe which runs a command in parallel over all inputs in a directory.
Teach Azure DevOps to enforce clang-format in parallel.
This script runs clang-format on the sources, then runs git status --porcelain on the result, redirected to stderr. If any output goes to stderr, Azure Pipelines marks the build as failed, which enforces that no changes were made to the repo by the clang-format pass.
Resolves#88