Added couchdb.path property parsing

The 'couchdb.path' property is introduced to support redirection/proxy. (ie.: http://hostname.com:8080/database)
Update CouchDbProperties.java

Added path property
Added path property to baseUri

Path property (empty if not defined) will be added to baseUri, after the last '/'
Merge pull request #31 from sebastien-cote/master

Added 'path' support to LightCouch