Naming convention

We need a naming convention:

1. What should be the prefix for project-specific CMake variables (see here)?

   suggestion: MEMMAN, MMAN, MEMM, MM

2. How should C++ user code include the public headers?

   suggestion: #include <memman/ClassName.hpp>

3. What should be the namespace of the C++ public API?

   suggestion: memman (currently: imb), do we need additional internal namespace?

4. How should C user code include the public header(s)?

   suggestion: #include <memman.h> (primary header) and #include <memman_error.h> (secondary headers if needed)

5. What should be the prefixes of the C functions and structures?

   suggestion: mm_ (public API) and mmi_ (internal functions)

6. Something else?