Remove unused options from installer

This change removes options -b <REFSPEC>, -m <MODULE>, --source,
--develop, --pullimages, --nodockerbuild from full_install_osm.sh and
install_osm.sh

It also remove unused unctions such as generate_docker_images and
cmp_overwrite.

Change-Id: I0c307a765671c4af8516afa97808b70baadb964f
Signed-off-by: garciadeblas <gerardo.garciadeblas@telefonica.com>