Merge 'kernel_callables_v3' into 'kernel_callables_v3-edit1'

doc/tutorial.rst

examples/fortran/ipython-integration-demo.ipynb

examples/fortran/matmul.floopy

examples/fortran/sparse.floopy

examples/fortran/tagging.floopy

examples/fortran/volumeKernel.floopy

loopy/__init__.py

loopy/check.py

loopy/frontend/fortran/__init__.py

loopy/ipython_ext.py

loopy/kernel/creation.py

loopy/kernel/instruction.py

loopy/library/reduction.py

loopy/preprocess.py

loopy/program.py

loopy/symbolic.py

loopy/target/opencl.py

loopy/transform/callable.py

loopy/transform/fusion.py

loopy/type_inference.py