Add tree levels to the vtk output

This commit add the option to output the octant levels to the vtk
visualization file.
Tweak the vtk octree level export logic

This commit corrects a couple snprintf errors and uses an uint8_t array
to store the level data during a binary vtk export.
Make separate primitive plots in timana.sh
Update/BREAK p4est api

Remove P*EST_CONNECT_DEFAULT.  There was no rationale for any default.
Remove P*EST_BALANCE_* enumeration/type; it was obsolete.
Introduce allow_for_coarsening parameter in p4est_partition.
Also improve some comments.
Bug fix

Memory was being free'd in an inappropriate if statement.
Bug fix

The cell data section of the vtu file was not being properly closed when
only writing octree level data.
Export octree level data in uint8 format
Clarify comments on p4est load/save
Merge 'ethan/vtk_write_levels' into develop
Run indent on p4est_vtk
Update AUTHORS