see #223

Signed-off-by: Cong Xu <cong.xu@intel.com>

1. Use Lustre Module in Darshan
2. Integrate DXLT IO tracing code into one module
3. Add hooks in POSIX and MPI Modules
4. Add Intel copyright
Signed-off-by: Cong Xu <cong.xu@intel.com>

1. Use Lustre Module in Darshan
2. Integrate DXLT IO tracing code into one module
3. Add hooks in POSIX and MPI Modules
4. Add Intel copyright
Signed-off-by: Cong Xu <cong.xu@intel.com>

- memory management is now entirely handled by darshan-core for
  module records
    * when registering new records, darshan-core returns the
      corresponding buffer to write it to, rather than allowing
      module to determine this
- modules now decide whether darshan-core should track record
  names by passing either a valid name or NULL to the register
  function
    * this allows modules to register records that aren't really
      tracked by darshan-core
- only the POSIX module has been ported to new changes for this
  commit

- move fopen/fopen64 wrappers to stdio module
- make infrastructure for tracking stream pointers based on similar fd
  infrastructure in posix
- define placeholder record structs
- wrappers don't actually do anything yet