disk, iaas: adding missing doc for class

we have added function without adding doc
should be handled by autodoc as we discused

Signed-off-by: William Dauchy <william@gandi.net>
iaas: fixing info message when using multiples resources

Signed-off-by: William Dauchy <william@gandi.net>
vm: choose HVM image as the default one

Signed-off-by: William Dauchy <william@gandi.net>
core, param: remove duplicates in images list

we have lots of duplicates since we list images from all datacenters
also sort the list so we can find the image more easily

Signed-off-by: William Dauchy <william@gandi.net>
disk: fixing disk_type when using snapshot profile

when creating a disk with a snapshot profile, we should use 'data' as
disk type.

Signed-off-by: William Dauchy <william@gandi.net>
docker: use HVM image by default

Signed-off-by: William Dauchy <william@gandi.net>