cmake flow of work

• cmake --help-module FindGLEW:
• cmake .. 
• will go into src/CMakeLists.txt then look for different external find_package()
• find_package(GLEW REQUIRED QUIET)
• goes into 'Pangolin/Modules' directory and looks for 'FindGLEW.cmake' file. If doesn't find it there then goes into '/usr/share/cmake-2.8/Modules/' to find
• If successful then following environment variables will be set inside the 'FindGLEW.cmake' file:
• GLEW_FOUND
• GLEW_INCLUDE_DIR or GLEW_INCLUDES
• GLEW_LIBRARIES or GLEW_LIBS
•  Printing env variable:
• MESSAGE( ${GLEW_INCLUDE_DIR}), if find_path(GLEW_INCLUDE_DIR ) is unsuccessful then message will print "GLEW_INCLUDE_DIR-NO-FOUND"
• sudo find /usr -iname '*glew*' -print (MOST USEFUL COMMAND)
• apt-cache search glew (FINDS THE AVAILABLE glew package for installation)
• Reference: How package finding works
• Reference: good
• Reference: with Visual Studio