api: add dnf.cli.CliError.

Plugins need it.
refactor: move MakeCacheCommand out into its own file.
transifex update
New version: 0.6.2
build 0.6.2-1
spec: requires rpm-plugin-systemd-inhibit (RhBug:1109927)
doc: minor fixes + repo references changed
doc: deplist command
deltarpm enabled by default (RhBug:1148208)