Before this commit, the condition to display the 'Save' button on object_view
actions was to check whether the user has 'Modify portal content' permission.

This check is moved to all scripts that are used as form action
(e.g. Base_edit), using guards.

Now, it's possible to add forms that can be saved under a different condition
than having 'Modify portal content' permission.

- Code refactoring and small optimizations.
- Really fix unwanted acquisition.
- ExternalMethod: fix security declarations.
- Fix role/permission checking for ExternalMethod called by a PythonScript
  with proxy roles.
- When editing an existing guard, modify it instead of always recreate one.
  no very useful here, but that's good practice: this is nicer for the ZODB
  and it's easier to browse the history. BT should do the same when upgrading.

testTask: new test to check that simulation inheritance can overwrite default ledgers set on portal type

testAccounting: makes test_createBalanceOnLedgerWithTransactionsWithNoLedger closer from Delivery Type expected behaviour

Add allow_tag_list and deny_tag_list parameter to WebPage_extractReferredObjectDict

HTML rendering tolerates list value, and renders are multi-lines.
Do the same in ODT renderer.

disable derived_merge in a query where it may cause the wrong result, instead of using DISTINCT trick.

* normalize URL in a case where we have several languages in URL.
* redirect to the web site root if HTTP_REFERER is not set.

erp5_web: set relative url path as absolute if no base_url found in WebPage_extractReferredObjectDict

This merge request makes full use of the base category "Ledger" in the Accounting and Project modules of ERP5.

Main modifications are : 
   * Adding the ledger property on every Accounting Transaction Types. It was already on Task Types.
   * Adding a new portal type of portal type for the types quoted above. It allows to define a list a ledgers directly on these types. These ledgers are the one allowed on the documents of each type.
   * New Delivery_init (Python) Script called by every "${}_init" script of the above type, and setting a default ledger at the creation of the documents
   * Adding a ledger field and column in the view defined like "[Entity|Account|...]_viewTransactionList" to only display the transactions belonging to a favorite ledger. The favorite ledgers can be defined in the Accounting Preferences. The list of displayed ledgers is the list of ledgers defined on the accounting portal types. If no ledger is defined, the field doesn't show up.
   * Adding a ledger field in every accounting report, to only generate them with the movements belonging to the ledgers of one's choice.
   * Adding the ledger parameter (and co) to the InventoryAPI to ease the queries on Inventory by ledger. Please note that the stock table now embeds a "ledger_uid" column


/reviewed-on nexedi/erp5!129

erp5_accounting: closing an Accounting Period generates one Balance Transaction per accounting ledger

BalanceTransaction.py updated to correctly index Balance Transactions with their ledgers.
_computeStockDifferenceList also now returns a correct result

erp5_mysql_innodb_catalog, erp5_research_item: Removes the parent_ledger related key and the code depending on it

erp5_accounting: adds "ledger" in the extra columns of AccountingTransactionModule_viewAccountingTransactionList

A new column ledger in the stock table and some related keys
(stored in erp5_mysql_innodb_catalog) have also been created
Adds tests for inventory queries based on ledger in testInventoryAPI

erp5_core: changes portal type filter on dynamic_class_generation_interaction_workflow and base_type_interaction_workflow to a portal group filter

These workflows now apply on every type belonging to the grouping type 'type_definition': Base Type and other portal types of portal types