Speed comparison with httpserver
I don't know how exactly this works behind the scenes, but it seems terribly slow at the moment, compared to a dumb httpserver. Here is the code tested, with `nim [file] c -r --checks:off --opt:speed >/dev/null`:

```
import jester, asyncdispatch, htmlgen

routes:
  const r = h1 "hello world"
  get "/":
    resp r

runForever()
```

and

```
import strutils, sockets, httpserver

proc handleRequest(client: Socket, path, query: string): bool {.procvar.} =
  client.send("<h1>hello world</h1>")
  client.close

run(handleRequest, Port(5000))
```

And here are the benchmarks for `ab -n10000 -c400 http://localhost:5000/`:

```
# Jester
Concurrency Level:      400
Time taken for tests:   13.004 seconds
Complete requests:      10000
Failed requests:        0
Total transferred:      840000 bytes
HTML transferred:       200000 bytes
Requests per second:    768.98 [#/sec] (mean)
Time per request:       520.171 [ms] (mean)
Time per request:       1.300 [ms] (mean, across all concurrent requests)
Transfer rate:          63.08 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        0   18 227.7      0    3004
Processing:    49   67 173.7     55   10387
Waiting:        6   67 173.6     55   10387
Total:         52   86 364.7     55   10387

Percentage of the requests served within a certain time (ms)
  50%     55
  66%     56
  75%     57
  80%     58
  90%     60
  95%     62
  98%     79
  99%    129
 100%  10387 (longest request)


# httpserver
Concurrency Level:      400
Time taken for tests:   0.438 seconds
Complete requests:      10000
Failed requests:        0
Total transferred:      200000 bytes
HTML transferred:       0 bytes
Requests per second:    22855.89 [#/sec] (mean)
Time per request:       17.501 [ms] (mean)
Time per request:       0.044 [ms] (mean, across all concurrent requests)
Transfer rate:          446.40 [Kbytes/sec] received

Connection Times (ms)
              min  mean[+/-sd] median   max
Connect:        1    2   1.2      2      13
Processing:     1    3   0.9      3       9
Waiting:        1    3   0.8      3       7
Total:          3    6   1.7      5      18

Percentage of the requests served within a certain time (ms)
  50%      5
  66%      5
  75%      5
  80%      5
  90%      8
  95%      9
  98%     10
  99%     16
 100%     18 (longest request)
```

The mean time per request is 520ms vs 17ms, so a 30x slowdown. Now, I get that Jester is supposed to do much more than a dumb httpserver, but 30x seems way off for me. Do you know why this is happening or whether it's going to get better?
