Refactors TaskRc parser to match previous version written by @ralphbean.
Adds tests; fixes #51.
Merge pull request #52 from coddingtonbear/issue_51

Refactors TaskRc parser to match previous version written by @ralphbean.
Merge configuration overrides into taskrc configuration.
Update existing use of config overrides to match new datatstructure.
Merge pull request #53 from coddingtonbear/handle_config_overrides

Merge configuration overrides into taskrc configuration.
Raise an exception if we can't parse configuration; ignore simple config values to allow storing complex ones.
Add AnnotationArrayField for handling idiosyncrasies of annotations.
Merge branch 'annotation_field' into inthe_am
Merge branch 'cautious_configuration_handling' into inthe_am