ctx: explicit error handling
ctx: impl. AddRepo, RemoveRepo, ListRepos
all: add repo-add, repo-ls and repo-rm subcommands
all: proper handling of local/remote repos and of 'file://' protocol
doc: add doc for repo-add, repo-ls and repo-rm
ctx: handle duplicate repo names
ctx: handle non-existant repo removal
utils: cleanup
ctx: fix 'lbpkr update', broken by pull#18
ctx: fix downloadFiles-deadlock when only one file to download
all: support for file:// protocol
ctx: batch downloads for 'lbpkr update'
Merge pull request #24 from lhcb-org/issue-21

test area for RPMs