Add COWMetric and do some code cleanups.
Merge pull request #37 from prometheus/cow-metrics

Add COWMetric and do some code cleanups.
Disable the timing-sensitive test TestSummaryDecay for now.

Obviously, the proper solution is to implement the test in a way that
does not depend on timing.
Merge pull request #39 from prometheus/beorn7/fix-travis

Disable the timing-sensitive test TestSummaryDecay for now.
Update Go download path and enable curl redirects.
Update used Go version from 1.2.1 to 1.4.
Drain collector channel when returning prematurely.
Merge pull request #40 from prometheus/drain-collect-channel

Drain collector channel when returning prematurely.
Add ProcessCollector and GoCollector

This change adds two new collectors to the prometheus package which
export metrics about a given or the current process.

* ProcessCollector exports metrics about cpu time, vss, rss, fd usage as
  well as the start time of a given process.
* GoCollector exports currently only the number of active goroutines.
Register process and go collectors by default