This wouldn't have worked with a clean tree since dependencies are
fetched at build time, so find_library would have returned NOTFOUND
since the fetch didn't happen

This commit:
- Add a dependency (automaticaly resolved/fetched at build time) on gtest
- requires you to define a VLMC_SAMPLES_PATH env variable when running
  the test application

This is done kinda quick and dirty, and we basically don't support the
absence of this library.

And comment

Christophe Courtaut authored 11 years ago and Hugo Beauzée-Luyssen committed 11 years ago

Signed-off-by: Christophe Courtaut <christophe.courtaut@gmail.com>
Signed-off-by: Hugo Beauzée-Luyssen <hugo@beauzee.fr>

This allowed too much laxism in includes :)