cmake error

Hi,

I'm trying to compile your program on Debian Wheezy, but get the following cmake error. I must be missing some dependency. Could you help?

Thanks

```
RTPS_EXPORTS
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
GLEW_LIBRARY
linked by target "rtps" in directory /home/michael/Public/projects/EnjaParticles/rtpslib
linked by target "flock.x" in directory /home/michael/Public/projects/EnjaParticles/test
linked by target "multi.x" in directory /home/michael/Public/projects/EnjaParticles/test
linked by target "outer.x" in directory /home/michael/Public/projects/EnjaParticles/test
linked by target "simple.x" in directory /home/michael/Public/projects/EnjaParticles/test
linked by target "sph.x" in directory /home/michael/Public/projects/EnjaParticles/test

-- Configuring incomplete, errors occurred!
```

Start by reproducing the CMake configuration error on Debian Wheezy and inspect the CMake files that define GLEW_LIBRARY for the rtps, flock.x, multi.x, outer.x, simple.x, and sph.x targets. Done means configuration completes without GLEW_LIBRARY set to NOTFOUND and these targets can proceed to build.

Written by the indexing model from the issue text.