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

src/plugins/simulator/xplane/xplane.pro

@@ -0,0 +1,28 @@
+load(common_pre)
+
+QT       += core dbus network
+
+TARGET = simulatorxplane
+TEMPLATE = lib
+
+CONFIG += plugin shared
+CONFIG += blackmisc blackcore
+
+DEPENDPATH += . $$SourceRoot/src
+INCLUDEPATH += . $$SourceRoot/src
+
+SOURCES += *.cpp
+HEADERS += *.h
+DISTFILES += simulatorxplane.json
+
+DESTDIR = $$DestRoot/bin/plugins/simulator
+
+win32 {
+    dlltarget.path = $$PREFIX/bin/plugins/simulator
+    INSTALLS += dlltarget
+} else {
+    target.path = $$PREFIX/bin/plugins/simulator
+    INSTALLS += target
+}
+
+load(common_post)