[Test] fix some size_t warnings

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3203 02a645c2-efd0-11dd-984d-ab748d24aa7e
Fix statements that called the assignment operator twice

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3204 02a645c2-efd0-11dd-984d-ab748d24aa7e
Introduce 'getValue' to avoid making std::map members mutable

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3205 02a645c2-efd0-11dd-984d-ab748d24aa7e
Additional uses for getValue with default value

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3206 02a645c2-efd0-11dd-984d-ab748d24aa7e
[Thermo] Make header files for SpeciesThermoInterpType descendants public

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3207 02a645c2-efd0-11dd-984d-ab748d24aa7e