Create a EML parser lib to digest eml document
Currently, the EML actor in Kepler can download eml document and parse it. After parsing, the entity information in eml document will be stored in java object and data file will be download into local file system and also be stored in relation db too.
We want to seperate this process from Kepler and make it as lib in eml module. So this library can be used in Kepler, Metacat and some other projects.