Revise code to load updates

Divide time span for updates in smaller steps such that the
dnb repos does not refuse to respond
Configure update process of Sigel data

Pass arguments to main method of Enrich.java to specify the start
point and the interval size in days; these values are used while
loading the Sigel updates from the dnb repository
Update url for dnb repository

Use proxy url "http://gnd-proxy.lobid.org/oai/repository" instead
of http://services.d-nb.de/oai/repository in order to start the
application from server
Create class for enriching of sample data (EnrichSample.java)

(For Unit tests and demonstration purposes hbz externally)
Update README.textile
Pass file path of dbs data to processDbs method of DBS

(Parallel to processSigel method in Sigel)
Reuse URIs for Sigel and DBS data sources
Make locations of data sources final
Merge pull request #21 from SBRitter/sigel-updates

Sigel updates