* Move NodeCollector into package collector
* Refactor collector enabling
* Update README with new collector enabled flags
* Fix out-of-date inline flag reference syntax
* Use new flags in end-to-end tests
* Add flag to disable all default collectors
* Track if a flag has been set explicitly
* Add --collectors.disable-defaults to README
* Revert disable-defaults flag
* Shorten flags
* Fixup timex collector registration
* Fix end-to-end tests
* Change procfs and sysfs path flags
* Fix review comments
* Add qdisc collector for Linux
This collector gathers basic queueing discipline metrics via netlink,
similarly to what `tc -s qdisc show` does.
* qdisc collector: nl-specific code moved, names fixed
- netlink-specific parts moved to github.com/ema/qdisc
- avoid using shortened names
- counters renamed into XXX_total
* Get rid of parseMessage error checking leftover
* Add github.com/ema/qdisc to vendored packages
* Update help texts and comments
* Add qdisc collector to README file
* qdisc collector end-to-end testing
* Update qdisc dependency to latest version
Update github.com/ema/qdisc dependency to revision 2c7e72d, which
includes unit testing.
* qdisc collector: rename "iface" label into "device"
