[Thermo] Use findXMLPhase in initThermoFile

This allows many constructors which take a filename to work with CTI files
directly, and to make use of the parsed XML cache.

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3185 02a645c2-efd0-11dd-984d-ab748d24aa7e
[Test] Show test class and test name for failing GTest tests

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3186 02a645c2-efd0-11dd-984d-ab748d24aa7e
[Test] Convert 'fracCoeff' test to GTest

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3187 02a645c2-efd0-11dd-984d-ab748d24aa7e
Make "string&" arguments "const string&"

This way, these functions can accept constant strings, including string
literals.

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3188 02a645c2-efd0-11dd-984d-ab748d24aa7e