Test reusing partition for mesh
Merged master into chris/hdf5-reuse-partition
Add restore partitioning parameter
Move parameter to function call
Do not make partition re-use arguments optional and small naming change for consistency.
Add parameter to XDMFFile too
Add read method to XDMFFile
Update test
Add interface to save point clouds to XDFM files.

Tests still needed.
Remove add/modified comments. Causes unecessary merge conflicts.
Some fixes for XDMF point clouds and add tests.
Merge branch 'garth/xdmf-point-cloud'
Merge branch 'chris/hdf5-reuse-partition'
Fix a dubious line of code in advection-diffusion demo.

Problem was picked up in c++11 mode.
Minor change in LogStream for C++11 compatibility.