Remove qmake build files

Removes qmake as a build system for building Qt Creator itself.
Keep them for some tests that are not completely moved to CMake yet.

Change-Id: I846c6ef65626b6dfae6375fdc85d00677aa8c2fb
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/libs/aggregation/aggregation.pro

@@ -1,9 +0,0 @@
-include(../../qtcreatorlibrary.pri)
-
-DEFINES += AGGREGATION_LIBRARY
-
-HEADERS = aggregate.h \
-    aggregation_global.h
-
-SOURCES = aggregate.cpp
-

src/libs/aggregation/aggregation_dependencies.pri

@@ -1 +0,0 @@
-QTC_LIB_NAME = Aggregation

src/libs/aggregation/examples/examples.pro

@@ -1,3 +0,0 @@
-TEMPLATE = subdirs
-
-SUBDIRS = text

src/libs/aggregation/examples/text/text.pro

@@ -1,14 +0,0 @@
-TARGET = text
-TEMPLATE = app
-QT += core \
-    gui
-DEFINES += AGGREGATION_LIBRARY
-INCLUDEPATH += ../../
-SOURCES += main.cpp \
-    ../../aggregate.cpp
-HEADERS += main.h \
-    myinterfaces.h \
-    ../../aggregate.h \
-    ../../aggregation_global.h
-FORMS += main.ui
-