v0.1.23, 2014-06-25 -- Rearrange TaskResult.timestart and timeend to return
                       UTC datetime
v0.1.22, 2014-06-22 -- Rename URL_UNFETCHABLE to URL_CONN_ERROR
v0.1.21, 2014-06-21 -- Added URL_TIMEOUT and UNSPECIFIED_ERROR fields
v0.1.20, 2014-06-14 -- Changed internal types for JSON serialization purposes
v0.1.19, 2014-06-13 -- Add meta data for TaskResultSet to store target_id and
                       job_id
v0.1.18, 2014-06-10 -- Schema addition: ArtifactSchema
v0.1.17, 2014-06-10 -- Remove all references to colander
v0.1.16, 2014-06-03 -- Port schemas to jsonschema, set TaskResult.err if
                       schema validation fails
v0.1.15, 2014-06-03 -- Switch from colander to jsonschema for validation
v0.1.14, 2014-06-01 -- Add MsgErrs to fields, logging updates 
v0.1.13, 2014-05-29 -- Rename TaskResults to TaskResultSet, add TaskResultSet
                       metadata (i.e. task-level errors like missing inputs)
v0.1.12, 2014-05-26 -- Add .msg helper for TaskResult
v0.1.11, 2014-05-26 -- Set whois raw as optional - may be empty result
v0.1.10, 2014-05-26 -- Added schemas for Host, Dom
v0.1.9,  2014-05-25 -- TaskResult now validated by colander schema
v0.1.8,  2014-05-25 -- Correct top level TaskSeed import
v0.1.7,  2014-05-25 -- Fix misc typos
v0.1.6,  2014-05-25 -- Add TaskSeed class for adding simple preset values
v0.1.5,  2014-05-23 -- Major overhaul adding TaskResults and TaskResult
v0.1.4,  2014-05-12 -- Minor update
v0.1.3,  2014-05-12 -- Added getattr handler for custom keys to ConstantDict
v0.1.2,  2014-05-12 -- Added IP field
v0.1.1,  2014-05-07 -- Initial release
