To date Roo has shipped with the Apache Felix OBR repository as the default. Given we weren't really using OBR very much so far, this wasn't a major issue.
This task is to modify the default URL to Roo's new repository file at httppgp://spring-roo-repository.springsource.org/repository.xml.zip. The httppgp:// prefix is pursuant to
ROO-1092. The file is also available via http://. An ASC armoured key is published at http://spring-roo-repository.springsource.org/repository.xml.zip.asc.
While making this change, also make the startup-time download of OBR indexes more reliable (eg if the user quickly shuts down Roo while the download thread is running, the network connection fails etc).