erp5_accounting: Add more columns to listbox in Accounting Transaction Module

Added source_trade, source and specialise to more columns and set as searchable columns
benchmarks: Even if it's unusual, some use cases may take less than 1 seconds to run.
Any blog "front" page should shows only a short blog description not entire blog post as this makes it impossible to read / follow.
use ODS instead of SXC for the temporary object in importing a spreadsheet.

export to SXC is no longer supported in LibreOffice 4.2.4.
credentials: only take into account persons with reference when looking up login from email

also simplify some error messages
relation field: fix error when displayed along with a matrixbox
knowledge_pad: fix resubmit of gadget preference

Step to reproduce:
- change preferences once
- go back to previous page with browser button
- submit again
- exception in KnowledgeBox_baseEdit because 'form_id' is sent twice
  and is transformed by Zope into a list
Add support for default value in category & value accessors

In Base._getAcquiredCategoryMembershipItemList, replace broken code by an exception.
add asComposedDocument.getProperty().

that tries to get the property from the original and its effecive models.
stop copying (deprecated) Payment Condition documents from Trade Condition to Order, and from Order to Packing List.