s/-->/a/ in father_price for gasstocks
[DB] Initial south migration for gas application

* default_settings.py: readded South among INSTALLED_APPS
* removed previous unusued migrations
* added initial migration for gas application
[DB] Some fields added to GASConfig, GASSupplierSolidalPact, GASMember

* GASMember, GASConfig, GASSupplierSolidalPact suspension fields
* GASConfig:
    send_email_on_close, registration token,
    use_order_planning, intergas_connection_set,
    some privacy settings
* GASSupplierSolidalPact:
    send_email_on_close

* added also South migrations to be applied with

    [ if you have never applied south migrations use:
        ./manage.py migrate myapp 0001 --fake
    ]

    ./manage.py migrate gas --no-initial-data

...some verbose_name reset to lower case. They should start lowercase.
Updated translations
Added fields in forms and implementation for send_email_on_close
Upgraded to version 0.9.7 with upgrade instructions
migrate change django-pro-history if needed
refactored stock and father_price

Note: cannot be possible to use the UnitConvertion table in order to avoid cascading if for measure unit.
minor locale change
Adjust balance for PACT
Limit supplier(Wallet) LedgerEntry to PACT

NOT FINISH
Some problem to obtain the results with the good sign
We cannot use Supplier's wallet or GAS's cash as is
We can try filtering LedgerEntry using sub transaction filtering
But the common economic pact operation doesn't use reference.

TODO: Find solution for filtering
1 -Supplier's wallet for on PACT
2 - and GAS's cash for one PACT
InterGAS on automatic close order and send email

The InterGAS implementation is under if order.group_id
TODO some debug on InterGAS when ready.

Use is_suspended for gas
Clean code
Doc upgrade to 0.9.7 . Forgotten to commit...
Added some TODO related to ProductPU,UnitsConversion and parent_price
Cleaned code of close_if_needed method. InterGAS support
Merge branch 'domthu-gassero-review' - InterGAS close and report
Block user interaction on POSTs and display popup...
Ajax image and raised layer for waiter popup
Fix for signed display of pact transactions

* Moved some accounting templatetags to
  base/templatetags/accounting_tags.py
* Written signed_ledger_entry_amount templatetag
Set default gas supplier order stock on OPEN transition