* Update Atomic Counters example to use atomic.Uint64
This commit updates the Atomic Counters example to follow atomic's
recommendation of using atomic.Uint64 instead of uint64 (same for other
types) and then calling methods on it, instead of calling
atomic.AddUint64().
It also updates the comments and empty lines a bit to look better on the
website.
* Run tools/build again
* Fix comments
This bugfix implements correct way to calculate source sha1 hash, before it will changed,
by propagation of unchanged sources.
This commit will also include regenerated static files and *.hash files.
Consistently use `time.Sleep`, instead of `runtime.Gosched`, to ensure all
goroutines can make progress. `Gosched` wasn't working in the playground
(ref #149).
Also stop trying to compare operation rates. This was tenuous given e.g. how
short the programs ran for, and with the `Sleep`s we now expect the rates to
be similar anyways.
Its not clear for newbies that using `time.Sleep` internally calls `runtime.Gosched()`
Its better to use it directly, moreover on my machine it shows x175 improvement in speed (7m requests per second vs 40k).
