output/httpd: move to dedicated directory

src/output/Registry.cxx

@@ -23,7 +23,7 @@
 #include "plugins/AlsaOutputPlugin.hxx"
 #include "plugins/AoOutputPlugin.hxx"
 #include "plugins/FifoOutputPlugin.hxx"
-#include "plugins/HttpdOutputPlugin.hxx"
+#include "plugins/httpd/HttpdOutputPlugin.hxx"
 #include "plugins/JackOutputPlugin.hxx"
 #include "plugins/NullOutputPlugin.hxx"
 #include "plugins/OpenALOutputPlugin.hxx"

src/output/plugins/httpd/HttpdInternal.hxx

@@ -25,8 +25,8 @@
 #ifndef MPD_OUTPUT_HTTPD_INTERNAL_H
 #define MPD_OUTPUT_HTTPD_INTERNAL_H
 
-#include "../Internal.hxx"
-#include "../Timer.hxx"
+#include "output/Internal.hxx"
+#include "output/Timer.hxx"
 #include "thread/Mutex.hxx"
 #include "event/ServerSocket.hxx"
 #include "event/DeferredMonitor.hxx"

src/output/plugins/httpd/HttpdOutputPlugin.cxx

@@ -21,7 +21,7 @@
 #include "HttpdOutputPlugin.hxx"
 #include "HttpdInternal.hxx"
 #include "HttpdClient.hxx"
-#include "../OutputAPI.hxx"
+#include "output/OutputAPI.hxx"
 #include "encoder/EncoderPlugin.hxx"
 #include "encoder/EncoderList.hxx"
 #include "system/Resolver.hxx"