Phase 1 of MOBDSK-674: Changed property names, swapped internal implementation of variable to a dictionary of AlfrescoProperty objects and change attachment methods to accept AlfrescoDocument instead of AlfrescoNode.
Removed AlfrescoWorkflowVariable class
Integrated changes from Taz and added checks for variable retrieval.
Final phase of MOBSDK-674: Introduced AlfrescoListingFilter onto AlfrescoListingContext then use this mechanism to filter processes by state.
Merge pull request #236 from gavincornwell/master

MOBSDK-674: Final phase of WorkflowService refactoring