Add WHOIS disclaimer text to ConfigModule

This fixes #23 for @parsoj by allowing a custom disclaimer to be
specified via dependency injection modules.

By making the disclaimer part of the dependency injection graph, it can
come from anywhere.

For example, if I was Donuts, I would have my own repository. I'd use an
external http_archive() repository for Domain Registry. Then I would
write my own Dagger @Component for each App Engine module. My Component
would have a list of Dagger Modules, which I copied from the Domain
Registry version. Then I would swap out ConfigModule with my own
DonutsConfigModule, which provides the same values.

So long as a method exists that @Provides @Config("whoisRegistry"), and
the module containing it is listed in the @Component, the dependency
injection graph becomes valid and complete for the whois package
(provided other dependencies are met.)

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=128082921

javatests/google/registry/whois/NameserverWhoisResponseTest.java

@@ -81,7 +81,7 @@ public class NameserverWhoisResponseTest {
   public void getTextOutputTest() {
     NameserverWhoisResponse nameserverWhoisResponse =
         new NameserverWhoisResponse(hostResource1, clock.nowUtc());
-    assertThat(nameserverWhoisResponse.getPlainTextOutput(false))
+    assertThat(nameserverWhoisResponse.getPlainTextOutput(false, "Doodle Disclaimer"))
         .isEqualTo(loadWhoisTestFile("whois_nameserver.txt"));
   }
 
@@ -89,7 +89,7 @@ public class NameserverWhoisResponseTest {
   public void getMultipleNameserversResponse() {
     NameserverWhoisResponse nameserverWhoisResponse =
         new NameserverWhoisResponse(ImmutableList.of(hostResource1, hostResource2), clock.nowUtc());
-    assertThat(nameserverWhoisResponse.getPlainTextOutput(false))
+    assertThat(nameserverWhoisResponse.getPlainTextOutput(false, "Doodle Disclaimer"))
         .isEqualTo(loadWhoisTestFile("whois_multiple_nameservers.txt"));
   }
 }