…GA protocol.

Removed logic that would return an empty list if optional `dimensions` were not used.

…ponse'.

…nstance with all attributes set.

… attributes set.

…esters without a high traffic site ;)). Added test documentation. All tests pass.

…returned in a Data Feed as object attributes.

Moved Data Feed parsing logic out of `Account.get_data()`. `DataSet` now takes care of much of the parsing directly as it creates its `DataPoint` elements.

Updated docs and tests for new features.

BACKWARDS INCOMPATIBLE:
Removed DataSet.dict property as this was broken for multiple metrics/dimensions (i.e. it only worked if there was *exactly* one dimension and one metric each).

Conflicts:
	src/googleanalytics/connection.py

…ounts.