Networkmanager (#134)

* rename ImageLoader* to Network*

* static NetworkManager

* NetworkManager queue arbitrary requests

* modify urlfetch to use NetworkManager

* urlfetchjson in terms of NetworkManager

* fetchurljson fetchurltimeout fetchurljsontimeout

special fetch url functions with various connects and functions to be
called

* operate on fetched data in the correct thread

* operate on fetched resources in correct thread

* networkmanager urlfetch functions

* expose urlfetch functions of networkmanager through util and
util::twitch

* add caller to util functions

* cleanup

* formatting

* urlPut function for NetworkManager and util::twitch

* cleanup worker (no more leak)

* use urlfetch for LazyLoadedImage::loadImage

* Rename NetworkManager methods (#1)

* Rename NetworkManager methods

Remove unused NetworkManager methods
Remove unused NetworkManager includes

Reorder includes in lazyloadedimage.cpp and urlfetch.hpp

* try to simplify code, might break everything

* fixed some more stuff?

src/widgets/logindialog.cpp

@@ -137,7 +137,7 @@ AdvancedLoginWidget::AdvancedLoginWidget()
     this->ui.buttonLowerRow.layout.addWidget(&this->ui.buttonLowerRow.fillInUserIDButton);
 
     connect(&this->ui.buttonLowerRow.fillInUserIDButton, &QPushButton::clicked, [=]() {
-        util::twitch::getUserID(this->ui.usernameInput.text(), [=](const QString &userID) {
+        util::twitch::getUserID(this->ui.usernameInput.text(), this, [=](const QString &userID) {
             this->ui.userIDInput.setText(userID);  //
         });
     });