Interface tests: tell what class is wrong.

Instead of just failing with no clue except that 0 is equal to 0...
[slaptool] Add getComputerPartitionList and getComputerPartitionInformation methods.
Revert "[slaptool] Add getComputerPartitionList and getComputerPartitionInformation methods."

This reverts commit 33d2a927e75fb4e6f6fd444ce55a209d639e2b44.
[slapos_hypermedia] Upgrade to new erp5_hal_json_style.

A few tests can be taken out of this BT to be put in erp5_hal_json_style.
[slapos_hypermedia] add hateoas URL preference.
changeSkin(), changeSkin() everywhere.
Hypermedia tests : correct order.
[slapos_hypermedia] Add support for other types of users, like Computer Partition.
[slapos_hypermedia] Add Instance_getHateoasRelatedHostingSubscription.
hypermedia Base_getHateoasMaster fixup
[slapos_hypermedia] Add Instance_getHateoasRelatedHostingSubscription. (tests)
slap: Add OpenOrder.getInformation() and OpenOrder.getOpenOrderList().
slapos CLI: add slapos list and slapos info.
[SlapTool] Add getHateoasUrl method.
slapos.slap: add getHateoasUrl support.
[slapos_erp5] testSlapOSERP5SkinSelection: add Hal skin.
[slapos.slap] Implement Partition.getInformation()