Handle Debugging:Queries

ToDo: apply the language distinction for all handle types

General Question:

• should the query input be the MPI opaque handle value or a pointer to a opaque handle?
  • Is taddr_t big enought to hold an opaque handle?

Subpages for specific Handle Queries:

• Communicator queries
• Request queries
• Status queries
• Type queries
• File queries
• Window queries
• Group queries