Handle undefined values in state

[JaydeeSaleCBOS]

handling of undefined values in state, so if the form doesn't exist it would create it and add it to store rather than fail over.

i.e
state = {
sampleForm: undefined
}

usage:
...mapFields(['sampleForm.name'])

this would fail, now succeeds and creates the name prop with undefined rather than failing

[coveralls]

Coverage decreased (-1.5%) to 98.529% when pulling 7b00afa on JaydeeSaleCBOS:master into ae30a03 on maoberlehner:master.