Drop "private" subfolders

"private" subfolders violate the structure of the project,
since the existence of all other subfolders is based on a
different principle.
In addition, there is no clear line between "private" and
"non private".

src/gui/CMakeLists.txt

@@ -17,6 +17,7 @@ add_library(qbt_gui STATIC
     downloadfromurldialog.h
     executionlogwidget.h
     fspathedit.h
+    fspathedit_p.h
     hidabletabwidget.h
     ipsubnetwhitelistoptionsdialog.h
     lineedit.h
@@ -28,8 +29,6 @@ add_library(qbt_gui STATIC
     powermanagement/powermanagement.h
     previewlistdelegate.h
     previewselectdialog.h
-    private/fspathedit_p.h
-    private/tristatewidget.h
     properties/downloadedpiecesbar.h
     properties/peerlistdelegate.h
     properties/peerlistsortmodel.h
@@ -79,10 +78,11 @@ add_library(qbt_gui STATIC
     transferlistsortmodel.h
     transferlistwidget.h
     tristateaction.h
+    tristatewidget.h
     uithememanager.h
     updownratiodialog.h
     utils.h
-
+    
     # sources
     aboutdialog.cpp
     addnewtorrentdialog.cpp
@@ -98,6 +98,7 @@ add_library(qbt_gui STATIC
     downloadfromurldialog.cpp
     executionlogwidget.cpp
     fspathedit.cpp
+    fspathedit_p.cpp
     hidabletabwidget.cpp
     ipsubnetwhitelistoptionsdialog.cpp
     lineedit.cpp
@@ -109,8 +110,6 @@ add_library(qbt_gui STATIC
     powermanagement/powermanagement.cpp
     previewlistdelegate.cpp
     previewselectdialog.cpp
-    private/fspathedit_p.cpp
-    private/tristatewidget.cpp
     properties/downloadedpiecesbar.cpp
     properties/peerlistdelegate.cpp
     properties/peerlistsortmodel.cpp
@@ -160,6 +159,7 @@ add_library(qbt_gui STATIC
     transferlistsortmodel.cpp
     transferlistwidget.cpp
     tristateaction.cpp
+    tristatewidget.cpp
     uithememanager.cpp
     updownratiodialog.cpp
     utils.cpp

src/gui/fspathedit.cpp

@@ -39,7 +39,7 @@
 #include <QToolButton>
 
 #include "base/utils/fs.h"
-#include "private/fspathedit_p.h"
+#include "fspathedit_p.h"
 
 namespace
 {

src/gui/gui.pri

@@ -15,6 +15,7 @@ HEADERS += \
     $$PWD/downloadfromurldialog.h \
     $$PWD/executionlogwidget.h \
     $$PWD/fspathedit.h \
+    $$PWD/fspathedit_p.h \
     $$PWD/hidabletabwidget.h \
     $$PWD/ipsubnetwhitelistoptionsdialog.h \
     $$PWD/lineedit.h \
@@ -26,8 +27,6 @@ HEADERS += \
     $$PWD/powermanagement/powermanagement.h \
     $$PWD/previewlistdelegate.h \
     $$PWD/previewselectdialog.h \
-    $$PWD/private/fspathedit_p.h \
-    $$PWD/private/tristatewidget.h \
     $$PWD/properties/downloadedpiecesbar.h \
     $$PWD/properties/peerlistdelegate.h \
     $$PWD/properties/peerlistsortmodel.h \
@@ -77,6 +76,7 @@ HEADERS += \
     $$PWD/transferlistsortmodel.h \
     $$PWD/transferlistwidget.h \
     $$PWD/tristateaction.h \
+    $$PWD/tristatewidget.h \
     $$PWD/uithememanager.h \
     $$PWD/updownratiodialog.h \
     $$PWD/utils.h
@@ -96,6 +96,7 @@ SOURCES += \
     $$PWD/downloadfromurldialog.cpp \
     $$PWD/executionlogwidget.cpp \
     $$PWD/fspathedit.cpp \
+    $$PWD/fspathedit_p.cpp \
     $$PWD/hidabletabwidget.cpp \
     $$PWD/ipsubnetwhitelistoptionsdialog.cpp \
     $$PWD/lineedit.cpp \
@@ -107,8 +108,6 @@ SOURCES += \
     $$PWD/powermanagement/powermanagement.cpp \
     $$PWD/previewlistdelegate.cpp \
     $$PWD/previewselectdialog.cpp \
-    $$PWD/private/fspathedit_p.cpp \
-    $$PWD/private/tristatewidget.cpp \
     $$PWD/properties/downloadedpiecesbar.cpp \
     $$PWD/properties/peerlistdelegate.cpp \
     $$PWD/properties/peerlistsortmodel.cpp \
@@ -158,6 +157,7 @@ SOURCES += \
     $$PWD/transferlistsortmodel.cpp \
     $$PWD/transferlistwidget.cpp \
     $$PWD/tristateaction.cpp \
+    $$PWD/tristatewidget.cpp \
     $$PWD/uithememanager.cpp \
     $$PWD/updownratiodialog.cpp \
     $$PWD/utils.cpp

src/gui/tristateaction.cpp

@@ -31,7 +31,7 @@
 #include <QString>
 #include <QWidget>
 
-#include "private/tristatewidget.h"
+#include "tristatewidget.h"
 
 TriStateAction::TriStateAction(const QString &text, QWidget *parent)
     : QWidgetAction {parent}