WIP on additional caching.

I'll convert this over to the new caching framework once
Ray adds it.



git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@2819 02a645c2-efd0-11dd-984d-ab748d24aa7e
Introduce a more general method of caching results

The ValueCache class is intended to standardize the method for implementing
value caching in Cantera, and to reduce the need to introduce additional member
variables to store cached variables and the thermodynamic state at which the
cached values were computed.

The initial usage is to replace the use of the m_tlast variable in IdealGasPhase
as an example.

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@2820 02a645c2-efd0-11dd-984d-ab748d24aa7e
[SCons] Allow 'clean' to be specified along with other targets

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@2821 02a645c2-efd0-11dd-984d-ab748d24aa7e
[Test] Fix platform-dependent output in test-IAPWSPres

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@2822 02a645c2-efd0-11dd-984d-ab748d24aa7e