Visual Studio defaults to 3-digit exponents when printing in scientific
notation. The tests now use a MSVC-specific function to change this
behavior when necessary.
The "cantera/kernel" directory is now part of the include path only
when building the Cantera kernel. All other modules include files in
this directory as "kernel/header.h".
This fixes a problem distinguishing between kernel/Kinetics.h and
kinetics.h on Windows.
