Fixed the debugIntegratorStages configuration option
Fixed handling of time-varying strain rate

The method of "pinning" the strain rate at the start of a timestep is no longer
used. Instead, the derivative is calculated exactly by the class implementing
the strain rate function.
Strain rate can now be an arbitrary function of time

Any Python function or callable object can be used to define the strain rate. At
the start of each global timestep, a new Chebyshev interpolant is computed,
which is then used to compute a(t) and a'(t). This approach avoids the
complexity and performance penalty of calling the Python function from the C++
solver class.
Install Cantera data files with the Python module
Add Ember's data directory to Cantera's search path