Background:
My main use case for msilib is for working with/editing existing MSI files and not creating MSI files.

As such I find much of the MSI API that I need missing.

While not difficult to re-create _msi.c with ctypes, I thought it might be good to use as much of _msi.c as implemented (faster :) )

Patch:
The patch exposes the 'h' member of msiobj as 'handle', and updates the doc to refer to them.

There are no tests in the patch yet. Any recommendation on tests? (just check that the member exists and has an 'int' value?