Add build option to turn deprecation warnings into errors.
Update deprecated object names in chapter_10.py tests.
Update deprecated object names in chapter_1.py tests.
Update some deprecated functions/class names.
Merge branch 'master' into garth/deprecation-error-option

Conflicts:
	dolfin/log/Logger.cpp
	test/unit/book/README
	test/unit/book/python/chapter_10.py
Move inclusion of petsc4py.i to the common module forcing it to be imported in all modules.
This forces the petsc4py typemaps for MPI_Comm to be used throughout the whole DOLFIN library
Add simple test of MPI_Comm when compiled with petsc4py
Do not reconstruct the cpp.FunctionSpace when turning a cpp.FunctionSpace from C++ to Python
Merge branch 'johanhake/fix-issue-197'
Merge branch 'garth/deprecation-error-option'