Added support for multiple different repository sets.
This may come handy in several scenarios:
* one may want to fetch data from local mirrors rather than
from canonical repository to save network bandwidth (handy
on build farms)
* one may want to use her own repositories (for example because
one is concerned about "cloud" or wants to build from "staging"
repositories in order to test changes)
A repository set is specifed by REPOSITORYSET variable (passed
either on command line or via environment variable). If no repository
set is specified, 'default' is used. Default set fetches source
from canonical repositories for the project.
syntax: glob
build
artifacts
reports
config.rb
.rake_tasks~