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>