Twiddle the order of the some of the export logic

This commit makes the order that the {write_tree,write_level,write_rank}
boolean logic gets visited consistent throughout the file.
lnodes: log order and number of global nodes

Conflicts:
	src/p4est_lnodes.c
lnodes: removed bad logic for tracking hanging edges.

The logic was: if the face isn't hanging, then the edges of the face can't be
hanging.  That is wrong, wrong, wrong.
partition: p.user_data is sent as-is, unless data_size > 0.
added p4est_source_ext

fix _load logging

added p4est_source_ext

Conflicts:
	src/p4est.c
	src/p4est_base.h
compiler warning: initialize two partition variables
added ray tracing to tsearch example
tsearch: make skipping time_search_1 an option
Revert "Run indent on p4est_vtk" to ease merge

This reverts commit 7557478b5ef16b3b012afc606a69c6bba031ed4b.
Merge 'ethan/vtk_write_levels' into develop
Indent p4est_vtk