This allows use of more extensive warning settings for the code that's actually
part of Cantera without generating excessive warnings on code automatically
generated code (e.g. f2c) or code that isn't part of Cantera proper (e.g. gtest,
libexecstream).
Include directories in the Cantera source tree should be listed first so that
they take precedence over headers from other installed copies of Cantera that
might end up on the include search path. This was potentially a problem when
Cantera was installed in the same location (e.g. /usr/local) as one of its
dependencies (e.g. Sundials).
The same logic applies to directories on the library link path.
The full set of .cti and .xml files to be installed is placed in build/data (for
use by the test suite) and copied to the CANTERA_DATA folder on installation.
This means that running a Python test will cause the Python extension
to be built, and that changes in the source will cause the Python tests
to rerun.
