It will ease transition.

It need to be applied also on trade model generated movements.

It needs to follow invoice definition in order to be correctly expanded.

This returns the full list of computer's software release (to install and
installed)

This allow coexists with outside of vifib objects.

For example unlimited person shall be analysed.

This prevent creating open order when adding person with business template

validate_action calls check consistency, which asserts existence of open order,
and as it uses catalog related key, such one have to be indexed correctly.

Also expose payment in sequence.

The sections are not definitive on Payment Transaction, so inventory API will
allow to easily find the payments, by checking balance with given states.

Payment shall represent fact that customer will give money.