New: Added Admin page (fixes #30)

Fixes #30

Following are the changes made:

* Supports save and reload of config.
* Picks up the config with a higher priority as mentioned in the README.
* Runs with ```grunt admin```
* Uses react and coffeescript

Any suggestions on how to go about on the below points?

* Support of https ( Need certificates. Related to #58? )
* Restart of other servers on save. (Should ```example.coffee``` be made a module?)
* Graph ( depends on #10 )
See [above comment](https://github.com/okTurtles/dnschain/pull/62/files#r20843790). DNSChain should run the admin stuff along with everything else it's running (there's only one process that's running, after all).