implemented p4est_connectivity_reduce.
added connectivity_reduce tests
fixed a typo
corrected a wrong comment for ghost_is_valid
fixed a typo
In test_conn_reduced chagend char* to const char*.
Added connectivity_is_valid assertion to p4est_connectivity_reduce
Removed unneccessary variable and is_valid test from p4est_connectivity_reduce
Added type casts to p4est_ghost_is_valid
removed unused variable
Add a geometry field to p4est_wrap
Revert "Add a geometry field to p4est_wrap"

This reverts commit ae342ebf5aa85264620214bb092633dc38812c51.
Maybe the geometry should not be forced to live in the wrapper.
Make p4est_wrap_new_conn extern
Merge remote-tracking branch 'johannes/develop' into develop
Replace assertions with checks in read_inp_stream
clean compile with CC=mpicxx
Indent p4est_wrap
Merge branch 'wrap' into develop
Add virtual destructor to p4est_geometry_t
Prepare using connectivity from geometry