Auto detect which Qt version to use (Qt5 has priority if both are installed). ROS Kinetic fix for vtk libproj.so not found bug.

guilib/src/CMakeLists.txt

@@ -48,7 +48,7 @@ SET(qrc
     ./GuiLib.qrc
 )
 
-IF("${RTABMAP_QT_VERSION}" STREQUAL "4")
+IF(QT4_FOUND)
     # generate rules for building source files from the resources
     QT4_ADD_RESOURCES(srcs_qrc ${qrc})
 
@@ -106,9 +106,9 @@ SET(INCLUDE_DIRS
 	${PCL_INCLUDE_DIRS}
 )
 
-IF("${RTABMAP_QT_VERSION}" STREQUAL "4")
+IF(QT4_FOUND)
     INCLUDE(${QT_USE_FILE})
-ENDIF()
+ENDIF(QT4_FOUND)
 
 SET(LIBRARIES
     ${QT_LIBRARIES} 
@@ -131,9 +131,9 @@ ADD_LIBRARY(rtabmap_gui ${SRC_FILES})
 # Linking with Qt libraries
 
 TARGET_LINK_LIBRARIES(rtabmap_gui rtabmap_core rtabmap_utilite ${LIBRARIES})
-IF("${RTABMAP_QT_VERSION}" STREQUAL "5")
+IF(Qt5_FOUND)
     QT5_USE_MODULES(rtabmap_gui Widgets Core Gui Svg PrintSupport)
-ENDIF()
+ENDIF(Qt5_FOUND)
 
 SET_TARGET_PROPERTIES(
      rtabmap_gui