geometry: Fixes for Jean Privat :p

Signed-off-by: Romain Chanoir <chanoir.romain@courrier.uqam.ca>
Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/geometry: rename IBoxed to Boxed

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib: addd nitunits to Numeric::value_of

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/geometry: intro the contructor Box::around

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
lib/geometry: refactor implementation of contains and intersects in 3d

Signed-off-by: Alexis Laferrière <alexis.laf@xymus.net>
geometry/boxes: adds init around in box3d and fixes intersections

Signed-off-by: Romain Chanoir <chanoir.romain@courrier.uqam.ca>