If user set create_tap to True then specify an interface (tap_gateway_interface) to use as gateway for
guest vm connected to tap interface, slapformat will configure route
to reache each guest from host: "route add -host tap_ip dev slaptapXX",
where tap_ip belong to the same network as the ip on tap_gateway_interface.
slapformat will also create network information for each tap
who will be used to configure network in guest vm.

This is a begining to create cluster of vm which are connected to
each other using tap interface, without bridge.

This commits aims to fix collision by using 2 diferent portal_skins folders for slapos_jio and erp5_hal_json_style, allowing us let both coexist on production.

Otherwise some prices are displayed with too many numbers after the dot.

Minor optimisations included.

This alarm is focus on keep only the minimal and usable set of bt5 installed, this helps on quick upgrades.

Relevant upgraders should be reincluded as constraints.