modify scalatra-swagger api docs generation to better support apiproperty annotation

Changes to the Model Property API generation
- take description from value field of apiproperty annotation instead of notes field
- use allowableValues property of apiproperty annotation
Merge pull request #267 from caoilte/2.2.x_2.9

modify scalatra-swagger api docs generation to better support apiproperty annotation
merge swagger changes
readme updates
readme changes