* Update golang.org/x/sys/unix
This allows to use simplified string conversion of Utsname members.
* Simplify Utsname string conversion
Use Utsname from golang.org/x/sys/unix which contains byte array
instead of int8/uint8 array members. This allows to simplify the string
conversions of these members.
* 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* Fix out-of-date inline flag reference syntax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
This creates a single metric like:
node_uname_info{domainname="(none)",machine="x86_64",nodename="desktop",release="3.16.0-48-generic",sysname="Linux",version="#64~14.04.1-Ubuntu SMP Thu Aug 20 23:03:57 UTC 2015"} 1
