Move CExecSock to ExecSock.h

As a result, Utils.h no longer has to include Socket.h and lots of stuff breaks.

Due to a severe case of lazyness, some of the code for CExecSock is still in
Utils.cpp. Feel free to fix if you really have to.

Signed-off-by: Uli Schlachter <psychon@znc.in>

Template.cpp

@@ -8,6 +8,7 @@
 
 #include "Template.h"
 #include "FileUtils.h"
+#include "ZNCDebug.h"
 #include <sstream>
 #include <algorithm>