Minor improvements

- WebFinger:  detect when to use http or https, better function naming
- RequestPool: add user agent

source/net/request_pool.d

@@ -1,8 +1,5 @@
 module net.request_pool;
 
-import core.thread;
-import core.sync.semaphore;
-
 import std.container;
 import std.parallelism;
 
@@ -32,6 +29,7 @@ class RequestPool {
     for (int i = 0; i < totalWorkers + 1; i++) {
       Request rq = Request();
       // TODO: add custom fields (such as user agent)
+      rq.addHeaders(["User-Agent": "apd (development)"]);
       this.m_requests ~= rq;
     }
   }