Changes to SUNDIALS API and core C/C++ needed for Python interfaces

[balos1]

This is the changes that are needed to enable the Python interfaces without the bindings themselves included to make the review process easier.

[balos1]

@gardner48 When this is merged into the feature/python-interfaces branch, I don't want the commits squashed so that I don't get a bunch of merge conflicts between this part1 branch and part2.

[gardner48]

General question on the C++ wrappers, how is error handling done? For examples, what happens if one of the C constructors returns NULL?

[balos1]

General question on the C++ wrappers, how is error handling done? For examples, what happens if one of the C constructors returns NULL?

The view will just hold a NULL object and error handling will be deferred to when it is used.