[MOD]Point Of Sale : Usability Improvement

addons/point_of_sale/pos.py

addons/point_of_sale/report/report_cash_register_view.xml

addons/point_of_sale/security/point_of_sale_security.xml

addons/point_of_sale/statement_view.xml

addons/point_of_sale/wizard/pos_box_entries.py

addons/point_of_sale/wizard/pos_box_out.py

addons/point_of_sale/wizard/pos_close_statement.py

addons/point_of_sale/wizard/pos_close_statement.xml

addons/point_of_sale/wizard/pos_open_statement.py

addons/point_of_sale/wizard/pos_open_statement.xml

addons/point_of_sale/wizard/pos_payment.xml