Simplified Function Arguments and Numerous Fixes

MTurkR v0.5

This release includes a large number of bug fixes, documentation corrections, and a large number of user-visible changes to function arguments meant to substantially simplify package use. Some highlights:

• GenerateQualificationRequirement now supports new comparators (given MTurk API update on 2014-07-17): "DoesNotExist", "In", and "NotIn". The "DoesNotExist" comparator allows requesters to effectively block workers who do not have, e.g., a requester-defined qualification. The "In" and "NotIn" comparators allow a boolean OR logical in QualificationRequirements (e.g., allowing a worker to be from the US or the UK) rather than having to create two separate HITs with different Locale restrictions. See documentation for details.
• Some features of of the basic API request functionality have changed: The signature argument to request now defaults to NULL and is generated automatically (authenticate is therefore deprecated). ParseErrorCodes is removed (now used internally in request). Arguments can be passed to request via a new ... argument in all functions.
• options('MTurkR.print') is deleted and replaced by options('MTurkR.verbose'). All functions will, temporarily, accept print arguments. All code should be updated to reflect the new terminology moving forward.
• Functions of the form *ToDataFrame have been replaced with as.data.frame S3 methods, which are handled by a global as.data.frame.MTurkResponse function.