title: Building FLANN with Cmake fails
body: <p>I am trying to build FLANN libraries in order to build PCL library afterwards.</p>
  
  <p>I get an error while using CMake to compile the source.
  I guess I am missing something very basic. Since I can't find a compiled library for my system I have to build it myself.</p>
  
  <p>With the command</p>
  
  <pre><code>~/flann-1.8.4-src/build&gt; cmake ..
  </code></pre>
  
  <p>I get</p>
  
  <pre><code>CMake Error at src/cpp/CMakeLists.txt:86 (add_library):
  No SOURCES given to target: flann
  CMake Error at src/cpp/CMakeLists.txt:32 (add_library):
  No SOURCES given to target: flann_cpp
  </code></pre>
  
  <p>This happens with flann 1.8.4 and 1.9.1 on a SLES11 operating system.</p>
  
  <p>Any hint?</p>
  
  <p>Here a complete transcription of what cmake says:</p>
  
  <pre><code>-- Could NOT find HDF5 (missing: HDF5_LIBRARIES HDF5_INCLUDE_DIRS) (found     version "")
  CMake Warning at CMakeLists.txt:76 (message):
    hdf5 library not found, some tests will not be run
  
  
  -- Could NOT find GTest (missing: GTEST_LIBRARY GTEST_INCLUDE_DIR GTEST_MAIN_LIBRARY)
  CMake Warning at CMakeLists.txt:115 (message):
    gtest library not found, some tests will not be run
  
  
  -- Found OpenMP_C: -fopenmp
  -- Found OpenMP_CXX: -fopenmp
  -- Found OpenMP: TRUE
  CMake Warning at src/matlab/CMakeLists.txt:79 (message):
    Cannot find MATLAB or Octave instalation.  Make sure that the 'bin'
    directory from the MATLAB instalation or that mkoctfile is in PATH
  
  
  hdf5 library not found, not compiling flann_example.cpp
  -- Could NOT find LATEX (missing: LATEX_COMPILER)
  -- Install prefix: /usr/local
  -- Build type: RelWithDebInfo
  -- Building C bindings: ON
  -- Building python bindings: ON
  -- Building matlab bindings: ON
  -- Building CUDA library: OFF
  -- Using OpenMP support: ON
  -- Using MPI support: OFF
  -- Configuring done
  CMake Error at src/cpp/CMakeLists.txt:86 (add_library):
    No SOURCES given to target: flann
  
  
  CMake Error at src/cpp/CMakeLists.txt:32 (add_library):
    No SOURCES given to target: flann_cpp
  -- Build files have been written to: ~/flann-1.8.4-src/build
  </code></pre>