Currently phIO, the wrapper layer between phSolver and phastaIO, only supports sync IO.

phIO will be extended to support posix IO.

0. Create mechanism to switch between posix and sync io. In the long term we would want to register appropriate functions to satisfy the phIO interface. Given that the current phastaIO should support both sync and posix this may not be a ideal approach; we would register the same functions for both modes.
1. Implement string handling for posix and sync. File and field names are slightly different; e.g. geombc-dat vs geombc.dat, connectivity interior1 vs connectivity interior linear tetrahedron .
2. Call the appropriate sequence of phastaIO fns to support posix in the phIO fns.

• phio_closefile_[read|write] syncio needs finalizephmpiio called after closefile
• phio_openfile_read syncio needs queryphmpiio and initializephmpiio called before openfile
• phio_openfile_write syncio needs initializephmpiio called before openfile

3. Resolve read and write function call logic differences in readnblk and elsewhere.