feat(core.object) Add isDefAndNotNull with test.
feat(core.object) Add object.get function with tests.
feat(data) Add data functions and accessors file with tests.
chore(graphs) Update codebase to use new accessors.
chore(examples) Update examples to use accessor strings.
chore(core.object) Use every to short-circuit computation.
chore(data.functions) Move data/data to data/functions.
chore(data.accessors) Rename accessor var to dimVal.
Merge pull request #64 from racker/accessor-strings

Accessor strings.