Update gitignore

Update gitignore
Create README.md
Update TODO
add extra fields to customer and more

Comentario commit 09/03/2014

-Add extra fields to customer:
business_name
shipping_company_data
contact_person_phone
contact_person_email
series_id
tax_condition

-Add extra fields to common:
customer_business_name
customer_mobile
customer_comments
customer_tax_condition
contact_person_phone
contact_person_email

-Modify customer edit visualization.
-Set customer series as new invoice series default.

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-Agrego campos extra a Cliente:
business_name --> Nombre comercial
shipping_company_data --> Empresa de envíos asociada
contact_person_phone --> Teléfono de persona de contacto
contact_person_email --> Mail de persona de contacto
series_id --> Serie de facturación
tax_condition --> Condición impositiva

-Agrego campos extra a Common:
customer_business_name
customer_mobile
customer_comments
customer_tax_condition
contact_person_phone
contact_person_email

-Modifico la visualización de la edición de un cliente.
-Establezco la serie de facturación del cliente como la por defecto en
una nueva factura.
update license

Actualizo licencia
Merge remote-tracking branch 'origin/master' into eFact