Merge remote-tracking branch 'upstream/next'
Merge branch 'martinal/fix-py3-multistage-issue'
Merge branch 'martinal/topic-remove-deprecated-code'
Merge branch 'johanhake/fix-writing-of-single-valued-MeshValueCollection'
Merge branch 'MarcoMorandini/remove-UF_long'
Merge branch 'nschloe/coverity4'
Merge branch 'tianyi/nls-tao-nonlinear'
Optimize read_mesh_value_collection in serial.

It seems that mesh.topology().global_indices() is not
always sorted, so the my previous implementation was
wrong. The new one is used in serial, while in parallel
we always use the distributed version, which is reasonably
fast also for small meshes.
Merge remote-tracking branch 'upstream/master'
Merge branch 'master' into peppu/optimize_hdf5_read_mesh_value_collection

Conflicts:
	dolfin/io/HDF5File.cpp
Merge branch 'peppu/optimize_hdf5_read_mesh_value_collection' into next