defer res_company.expense_currency_exchange_account_id

fixes updates on res_company
add auth_ldap
some crm fixes

 * discriminators
 * crm_case_channel -> crm_tracking_medium
 * crm_lead.categ_id m2o -> m2m
 * remove some __forget__ for fields we don't have
add some accounting
add product
fix res_partner_bank and crm_case_stage
fix crm_segmentation
fix crm_lead
remove account_journal_column which was removed from odoo
add migration test script
Merge branch 'develop'