Literature module and testing improvements

o Improves the generic literature coercion
  o improves the automatic detection of coercion types to eml

o Finishes up literature testing
  - Renames the test file for literature to fix typo
  - Adds test for the rest of literature module coercions
    and auto detections

o belongs to issue #27
Includes the literature module where it can occur

Belongs to issue #27
Merge pull request #89 from cpfaff/litrature

Litrature