Expose pure MASA c++ interface

[nicholasmalaya]

Instead of forcing user to call sets of functions, al la:

masa_init();
masa_init_param();
masa_sanity_check();

etc.

Put together the c++ interface so that all are member functions of a masa class, i.e.:

MASA foo;
foo.init();
foo.init_param();
foo.sanity();

etc.

Should not be too hard. Will require reworking masa core routines, as well as wrappers for c and fortran. Also, all cpp regression tests will need fixin'.

Was requested by @pbauman and @vikramvgarg. This is not an API change but significant enough I would like it to be independent of current masa release targets (0.44). Likely will be named 0.50.

[roystgnr]

Why a new MASA class rather than the existing MasterMS class?

[nicholasmalaya]

This is not a new class -- as the title implies the intent is to expose the existing class and methods.

[roystgnr]

I see "MASA foo;" in the issue.

I see "namespace MASA" but not "class MASA" in the code. Where is the existing class?