Refactor qmake SUBDIRS structure

The big swift.pro is refactored by the correct usage of SUBDIRS
template. The following additional changes are made:
- Removed '_' from all targets and folder names
- Aligned parent folder and target name

refs #461

samples/hotkey/hotkey.pro

@@ -0,0 +1,23 @@
+load(common_pre)
+
+QT       += core gui dbus network
+
+greaterThan(QT_MAJOR_VERSION, 4): QT += widgets
+
+TARGET = samplehotkey
+TEMPLATE = app
+
+CONFIG   -= app_bundle
+CONFIG   += blackmisc blackinput blackcore blackgui
+
+DEPENDPATH += . $$SourceRoot/src
+INCLUDEPATH += . $$SourceRoot/src
+
+SOURCES += *.cpp
+
+DESTDIR = $$DestRoot/bin
+
+target.path = $$PREFIX/bin
+INSTALLS += target
+
+load(common_post)