Show invoice's lines to pay

Following https://discuss.tryton.org/t/renegotiating-payment-term-on-invoices/2331/8

assigned to @pokoli

added accounting type::feature + 1 deleted label

added 1 deleted label and removed 1 deleted label

review266821007 updated at https://codereview.tryton.org/266821007/#ps268931029

New changeset c174fe563e2b by Sergi Almacellas Abellana in branch 'default':
Show lines to pay on invoice form
https://hg.tryton.org/modules/account_invoice/rev/c174fe563e2b

added 1 deleted label and removed 1 deleted label

closed

New changeset 679a34c1d630 by Sergi Almacellas Abellana in branch 'default':
Show lines to pay on invoice form
https://hg.tryton.org/tryton-env/rev/679a34c1d630