Another pass through README.rst.
a_to_b -> b_from_a in context.py
a_to_b -> b_to_a in maps.py
a_to_b -> b_from_a in paralleltest_localarray.py
a_to_b -> b_from_a in localarray.py
Merge pull request #243 from cowlicks/to-from-switch

Use `X_from_Y` rather than `Y_to_X`.
size -> global_size
data -> local_data
Merge pull request #244 from cowlicks/global-size

`size` -> `global_size`
Changed some plots to 5x9, added fixed random seed.
Merge branch 'master' into protocol-example-plots