[Cython/Reactor] Print messages from exceptions raised in Python callbacks

Unlike the normal case for CallbackError, where the error message is visible
when it is re-raised in Python, errors occuring during reactor network
integration aren't necessarily terminal, so they can't simply be re-raised after
returning to Python. But we still want to display the information they contain,
so we need to extract that information from the Python exception objects in the
what() function that is called by cvodes_rhs.

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3170 02a645c2-efd0-11dd-984d-ab748d24aa7e
Remove redundant copy of h2o2.xml

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3171 02a645c2-efd0-11dd-984d-ab748d24aa7e
Add user-specified directories to the beginning of the search path

This way, users are able to override the defaults.

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3172 02a645c2-efd0-11dd-984d-ab748d24aa7e
[SCons] Clean up additional data files

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3173 02a645c2-efd0-11dd-984d-ab748d24aa7e
Add missing reaction to "h2o2" mechanism

This mechanism, which is supposed to be the H2 mechanism extracted from GRI-3.0,
was actually missing the reaction H+O2+M <-> HO2+M. This updates the original
input file, regenerates h2o2.cti, and updates the blessed output file for one
test (which changed because the newer version of ck2cti actually retains the
given precision of the transport properties).

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3174 02a645c2-efd0-11dd-984d-ab748d24aa7e
[Cython/Reactor] Raise exception for unrecognized keyword arguments

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3175 02a645c2-efd0-11dd-984d-ab748d24aa7e
[Cython/Reactor] Add Reactor keyword argument 'volume'

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3176 02a645c2-efd0-11dd-984d-ab748d24aa7e
[Transport] Fix handling of default value for acentric_factor

If acentric_factor isn't specified in the CTI, don't include it when generating
the XML.

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@3177 02a645c2-efd0-11dd-984d-ab748d24aa7e