NEW PROVIDER: ClouDNS (#578)

* ClouDNS: first version of provider
* ClouDNS: documentation
* ClouDNS: code cleanup
* ClouDNS: GetNameservers now uses ClouDNS API to fetch NS servers list
* ClouDNS: CAA support
* ClouDNS: TLSA support
* ClouDNS: tests credentials now use variables instead of hardcoded values
* ClouDNS: SSHFP support
* ClouDNS: export only necessary methods

docs/_providers/cloudns.md

@@ -0,0 +1,58 @@
+---
+name: ClouDNS
+title: ClouDNS Provider
+layout: default
+jsId: CLOUDNS
+---
+# ClouDNS Provider
+
+## Configuration
+In your credentials file, you must provide your [Api user ID and password](https://asia.cloudns.net/wiki/article/42/). 
+
+Current version of provider doesn't support `sub-auth-id` or  `sub-auth-user`. 
+
+{% highlight json %}
+{
+  "cloudns": {
+    "auth-id": "12345",
+    "auth-password": "your-password"
+  }
+}
+{% endhighlight %}
+
+## Metadata
+This provider does not recognize any special metadata fields unique to ClouDNS.
+
+## Usage
+Example Javascript:
+
+{% highlight js %}
+var REG_NONE = NewRegistrar('none', 'NONE')
+var CLOUDNS = NewDnsProvider("cloudns", "CLOUDNS");
+
+D("example.tld", REG_NONE, DnsProvider(CLOUDNS),
+    A("test","1.2.3.4")
+);
+{%endhighlight%}
+
+## Activation
+[Create Auth ID](https://asia.cloudns.net/api-settings/).  Only paid account can use API
+
+## Caveats
+ClouDNS does not allow all TTLs, but only a specific subset of TTLs. The following [TTLs are supported](https://asia.cloudns.net/wiki/article/188/):
+- 60  (1 minute)
+- 300 (5 minutes)
+- 900 (15 minutes)
+- 1800 (30 minutes)
+- 3600 (1 hour)
+- 21600 (6 hours)
+- 43200 (12 hours)
+- 86400 (1 day)
+- 172800 (2 days)
+- 259200 (3 days)
+- 604800 (1 week)
+- 1209600 (2 weeks)
+- 2419200 (4 weeks)
+
+The provider will automatically round up your TTL to one of these values. For example, 350 seconds would become 900
+seconds, but 300 seconds would stay 300 seconds. 

docs/provider-list.md

@@ -61,6 +61,7 @@ provided to help community members support their code independently.
 
 Maintainers of contributed providers:
 
+* ClouDNS @pragmaton
 * digital ocean @Deraen
 * dnsimple @aeden
 * gandi @TomOnTime