Search resources by keyword ID (e.g. GET /keyword/44141956)
Replace index strings with an enum
Move nested enum types out of the application controller class
Extract statics out of the document model class
Move search field mappings into the index enum
Extract category parameter dispatch into an enum
Extract search result field dispatch into an enum
Move query construction into the index enum
Rename class with remaining statics for searching documents
Move TableRow to the views package
Update and add file headers, some formatting
Merge pull request #51 from fsteeg/resource-by-keyword-id

Search resources by keyword ID, and some refactorings