Add citest.ps1 PowerShell script to run the tests.

Refactor citest.sh to enable local testing by developers.

Sets up a linux host to prepare for a build.

Script to set up dependencies on a macOS build system.

On Linux (where we run valgrind) allocate a smaller buffer, but still an
insanely large size.  This will cause malloc to fail but will not cause
valgrind to report a likely error with a negative-sized malloc.

Keep the original buffer size on non-Linux platforms: this is
well-tested on them and changing it may be problematic.  On macOS, for
example, using the new size causes `malloc` to print a warning to
stderr.

The leaks process is not good about handling children.  Ensure that its
child is `nohup`ed so that the grandparent shell won't wait for it to
exit.

Early Windows TLS 1.2 implementations have an issue during key exchange
with OpenSSL implementations that cause negotiation to fail with the
error "the buffer supplied to a function was too small."

This is a transient error on the connection, so when that error is
received, retry up to 5 times to create a connection to the remote
server before actually giving up.

Instead of trying to run coverity builds during the regular PR process,
run them during a regularly scheduled cron process.  These only need to
run nightly, so it makes sense to bring them out of the PR process.

Don't just free the push status structure, actually free the strings that were
strdup'd into the struct as well.

Don't just free the spec vector, also free the specs themselves.

Free the url field when resetting the stream to avoid leaking it.

Explicitly run from the build directory, not the source.  (I was
mistaken about the default working directory for VSTS agents.)

Our build YAML is becoming unweildly and full of copy-pasta.  Simplify
with templates.