allow a request to be processed in a job

Now we allow a request to be passed into a job queue,
and after the job finishes the request is passed into
a controller again. In order to achieve this we have
a requests queue in System, when we put a request
to the job this Request structure is preserved in the
queue and for a new request a new Request is added to
the queue.

while here:
- remove App::Lock()/Unlock(), use scoped locking
- fix: Plugin now has a Call method which takes ModelConnector
  and a logger (used in multithreaded environment)
- BaseThread has a main_model_connector pointer
  to the main (from the main thread) model connector
- the FastCGI structure fcgi_request moved from App to Request
- some methods for handling requests moved from App to Request
- small refactoring in main.cpp
- add Http class (a http client)

winixd/templates/templates.cpp

@@ -646,7 +646,7 @@ void Templates::CreateFunctions()
 	ezc_functions.Insert("content", content);
 
 
-	plugin->Call((Session*)0, WINIX_TEMPLATES_CREATEFUNCTIONS, &ezc_functions, &ezc_objects);
+	plugin->Call(WINIX_TEMPLATES_CREATEFUNCTIONS, &ezc_functions, &ezc_objects);
 
 
 	Ezc::Objects<HtmlTextStream>::Iterator i = ezc_objects.Begin();
@@ -840,7 +840,7 @@ using namespace TemplatesFunctions;
 	ReadIndexTemplates();
 	ReadChangeTemplates();
 
-	plugin->Call((Session*)0, WINIX_ADD_TEMPLATE);
+	plugin->Call(WINIX_ADD_TEMPLATE);
 
 	patterns.RebuildCache();
 	ezc_blocks.CacheObjects(ezc_objects);