- post list view gadget and details

- the json form is built from the form definition (hardcoded for now) and the context-document info
- only on post view gadget for now

- web site and pages
- changes in jio configuration

1. a inventory report module is added which user can add inventory report


2. in inventory report,  user should put information such as Owner, Warehouse... then call calculate product stock action


3. one line per product is then added automatically with current total quantity and total asset price


![Screenshot_2018-12-12_at_17.42.24](/uploads/98f8a4af66faadfdfd1d99b4400ff687/Screenshot_2018-12-12_at_17.42.24.png)


/reviewed-on nexedi/erp5!806

if i have a url like:
https://erp5xxx/form_idxxx?relative_item_relative_url=item_module/7817

with the old way, form id will be 7817

/reviewed-on nexedi/erp5!824

According to pep-0263, python scripts can define encoding magic on
first or second line.
If we use for example such a script:

```python
  # coding: utf-8
  return "héhé"
```

then using .read() was wrong, because it return the script with headers,
ie:

```python
  ## Script (Python) "test_coding"
  ##bind container=container
  ##bind context=context
  ##bind namespace=
  ##bind script=script
  ##bind subpath=traverse_subpath
  ##parameters=
  ##title=
  ##
  # coding: utf-8
  return "héhé"
```

so the coding magic is no longer in first line and pylint complains
with error like:

Cannot decode using encoding "ascii", unexpected byte at position 11 (invalid-encoded-data)]

/reviewed-on nexedi/erp5!825

only calculate exchange rate if necessary
use transaction cache
make getExchangeRate as local function

remove useless test_21
update test_20 with various packing list

multiple owner test case
multiple cancel packing list test
circular movement test

- refactoring in scripts to create threads and replies
- new query to get posts

This method is used to import ZODB Components when fallback on filesystem is needed
and used when loading Document and Extension Components.

1,000,000 executions:
  * Before:
    timeit("erp5.component.extension.find_load_module(module_name)",
           setup="import erp5.component.extension; module_name='Hoge'")
    59.073
    59.324
  * b45914fa ExternalMethod optimization:
    timeit("__import__('erp5.component.extension.' + module_name, fromlist='*', level=0)",
           setup="module_name='Hoge'")
    1.754
    1.845
  * This commit:
    timeit("import_module('erp5.component.extension.' + module_name)",
           setup="from importlib import import_module; module_name='Hoge'")
    1.346
    1.311
    => Faster because import_module() calls __import__() without fromlist (not
       needed as it returns module from sys.modules after this) and level
       parameters.
    => Introduced in python3 and backported to python2.7. Recommended over
       __import__ in Python documentation for non-internal usage and when
       getting the module itself and not its top-level one.