Support QGLViewer-qt5 and enable Qt5 by default

Thanks to kazuki0824 and anasarrak.

CMakeLists.txt

@@ -6,7 +6,7 @@ set(CMAKE_POSITION_INDEPENDENT_CODE ON)  # enables -fPIC in applicable compilers
 
 option(BUILD_OCTOVIS_SUBPROJECT "Build targets from subproject octovis" ON)
 option(BUILD_DYNAMICETD3D_SUBPROJECT  "Build targets from subproject dynamicEDT3D" ON)
-option(OCTOVIS_QT5 "Link Octovis against Qt5?" NO)
+option(OCTOVIS_QT5 "Link Octovis against Qt5?" ON)
 
 if(OCTOVIS_QT5)
 	# Compiling against QT5 requires C++11.

octovis/CMakeModules/FindQGLViewer.cmake

@@ -1,5 +1,5 @@
 # Find QGLViewer library
-# Looks for a system-wide version of libQGLViewer (qglviewer-qt4 in Ubuntu).
+# Looks for a system-wide version of libQGLViewer (qglviewer-qt4 or 5 in Ubuntu).
 # If none is found, it builds and uses the local copy in "extern"
 #
 # Many thanks to L. Ott for assistance!
@@ -23,7 +23,11 @@ FIND_PATH( QGLViewer_INCLUDE_DIR qglviewer.h
     ${QGLVIEWER_BASE_DIR}
 )
 
-FIND_LIBRARY( QGLViewer_LIBRARY_DIR_UBUNTU NAMES qglviewer-qt4 QGLViewer-qt4)
+IF( QT4_FOUND )
+    FIND_LIBRARY( QGLViewer_LIBRARY_DIR_UBUNTU NAMES qglviewer-qt4 QGLViewer-qt4)
+ELSE()
+    FIND_LIBRARY( QGLViewer_LIBRARY_DIR_UBUNTU NAMES qglviewer-qt5 QGLViewer-qt5)
+ENDIF()
 FIND_LIBRARY( QGLViewer_LIBRARY_DIR_WINDOWS QGLViewer2 ${QGLVIEWER_BASE_DIR})
 FIND_LIBRARY( QGLViewer_LIBRARY_DIR_OTHER QGLViewer ${QGLVIEWER_BASE_DIR})
 
@@ -119,4 +123,4 @@ ENDIF()
 # You need to use qmake of QT4. You are using QT3 if you get:
 
 #CMakeFiles/octovis.dir/ViewerWidget.cpp.o: In function `octomap::ViewerWidget::ViewerWidget(QWidget*)':
-#ViewerWidget.cpp:(.text+0x1715): undefined reference to `QGLViewer::QGLViewer(QWidget*, QGLWidget const*, QFlags<Qt::WindowType>)'
+#ViewerWidget.cpp:(.text+0x1715): undefined reference to `QGLViewer::QGLViewer(QWidget*, QGLWidget const*, QFlags<Qt::WindowType>)'