[FIX] corrected a word in a comment

closes #3423
[FIX] doc: fit code example to new API

When using this code as is, the 'ids' variable throws an exception for not
being defined. In the new API, 'ids' is no longer given as a function variable
but as a variable within 'self'.

close #3406
[IMP] account: Add multi-company record rule for analytic entries report

As a multi-company rule is already present for account.analytic.account and account.analytic.line, should have one on the report on both of them.
[FIX] point_of_sale: details of sales report: include discount when computing taxes

Also, fixed a typo in the report's view.
[CHG] doc: promote individual view types to document toplevel
[FIX] doc: graph <field> does not use :grouping

see #3403 and 7ad4af8
[DOC] fields.py: oldname key
[FIX] payment_paypal: env field has been renamed with environment in 8.0

as env is a built-in orm variable.
[IMP] doc: add some diagrams to workflow doc

Also move transitions to the bottom of the document, and try to clarify the
documentation for split, join and activity kinds.
[FIX] Remove duplicate "Can be purchased" filter.

Duplicate product filter "To Purchase" and "Can be Purchased". Same search
criteria and same name, so removing one doesn't affect people who were
referencing it (e.g. with search_default_* key in context).  Left the one
named "Can be Purchased" because consistent with the equivalent sale filter
"Can be Sold".

Fixes #2718, closes #2864
[FIX] account: recompute invoice residual amount when one of its move lines is totally reconciled
Fixes #3395
[FIX] account: correctly compute residual amount of partially reconciled multi-term invoices.
Fixes #1213